(I) Introduction
In Ultrasociety, evolutionary scientist Peter Turchin examines the broad sweep of human history, particularly the last 10,000 years, in an attempt to answer a crucial question:
The central question of this book is why, during the past 10,000 years, large-scale, complex societies have replaced small-scale societies (229).
(Unless otherwise stated, all numbers in parentheses are page numbers from Ultrasociety (Turchin, 2016).)
Around 10,000 years ago, says Turchin, human societies were composed of simple, small-scale, intimate villages of relatives and friends, whose social lives were made up of face-to-face interactions, although they were constantly threatened by outsiders. These societies have been replaced by large, complex societies which, while generally peaceful, are made up overwhelmingly of strangers, and are characterised by steep inequalities (17, 31, 36). The term “ultrasociality” refers to this extreme sociality of human beings, who are able to cooperate in these very large groups of genetically unrelated strangers (3, 14-5).
These changes happened too fast to be explained by genetically-based evolution, says Turchin (17). Turchin calls his alternative approach “destructive creation”, and he locates it, and the “cultural multilevel selection” with which it is linked, within the Darwinian tradition (45-94).1
I am entirely sympathetic with Turchin’s focus on large-scale and long-term processes and patterns, and I agree that the changes he mentions are among those that demand explanation. Moreover, any attempt to explain long-term historical development through a (more or less) Darwinian mechanism would be of interest on a website dedicated to expounding and developing a (non-Marxian) version of historical materialism that also utilises more or less Darwinian mechanisms. It is because Turchin's destructive creation and my Darwinian historical materialism share the same conceptual space, in attempting to use Darwinian insights to develop a theory of human history, that I have felt it necessary to to interrogate Turchin's argument at such length in order to clarify (at least for myself) the similarities and differences between the two theories.
I shall not, except perhaps in one or two places, question the historical evidence that Turchin presents. This does not mean that I endorse this evidence, but I prefer to focus upon the cogency of the theoretical claims that Turchin makes, and their consistency with the account of history that he presents.
While there is much to agree with in Ultrasociety, I also find much to disagree with. In particular, there are inexplicable omissions in his theory, and Turchin makes claims that are inconsistent both with each other and with his underlying theory. Consequently, this review essay is highly critical and (unfortunately) very lengthy (it was written over a very long isolation during the Covid 19 pandemic). It is perhaps worthwhile, therefore, to sketch out its general structure.
This can be thought of as an essay of two unequal parts. After this introduction, most of the first part (sections II to VI) is primarily concerned with issues of theory (with some reference to historical materials), while the second part (sections VII to XIII) switches the focus to matters of history (though with many references to the preceding theoretical issues).
To be more specific, section II briefly outlines the theory of natural selection. Section III describes some distinctive elements involved in constructing a Darwinian theory of history, and section IV outlines a Darwinian historical materialism. This should help to clarify the theoretical basis of my disagreements with Turchin. Section V outlines (what I take to be) Turchin’s theory of destructive creation in some detail, and section VI offers some general criticisms of that theory.
The second, and longer, part of the essay begins (section VII) with an account of Turchin’s overarching view of history, and then (sections VIII to XIII) turns to more detailed examination, and criticism, of his account of some important historical developments, arguing that the explanations he gives are not always consistent with the theory he proposes, or with some of the historical claims he makes elsewhere. I will usually suggest how Darwinian historical materialism would approach the same historical material, and this may help to clarify the explanatory structure that I am proposing. The conclusion (section XIV) attempts to draw together these criticisms, and makes some suggestions as to how Turchin could address them.
(II) Natural Selection
Natural selection claims that, within organic populations, differential reproductive success increases the frequency of those inherited variations that enhance (relative) reproductive success. Within these populations, consequently, there will be persistent tendencies towards increasing reproductive success and, therefore, population growth.2
But what is it that explains which variations, in particular cases, will enhance reproductive success (and that therefore explains which variations will tend to increase in frequency because of differential reproductive success)? The standard answer is that it is the organisms’ relationship to their environment that explains which variations will enhance reproductive success and which will not (Sober, 1993, 20-1, 68, 73).
So, for example, the evolution on the Galapagos islands of different varieties of finches descended from the same ancestral population is explained, not simply by identifying natural selection as the evolutionary force that has produced these varieties, but also by reference to the different bird-environment relationships prevailing on these different islands (Sober, 1993, 12).
We therefore need to amend our formulation of natural selection as follows: within organic populations, differential reproductive success increases the frequency of those inherited variations that, given the relevant organism-environment relationship, enhance (relative) reproductive success. So the organism-environment relationship explains which inherited variations will enhance reproductive success and which will not, and therefore explains which inherited variations will, because of this differential reproductive success, increase in frequency and which will decrease.
Whether the tendencies to increasing reproductive success and population growth will be realised as long-term trends depends, therefore, upon the prevailing organism-environment relationship, particularly the extent to which a (growing) population can continue to extract resources from its environment, given that resources are always limited and there is usually competition from other organisms.
So there are two crucial questions that any attempt to use Darwinian styles of explanation to understand human history must answer. First, what are the selective mechanisms involved? And second, what is it that explains what those mechanisms actually select?
(III) A Darwinian Theory of History
In attempting to formulate an approach to human history that utilises the insights of Darwinism, we should recognise that cultural traits are behaviourally transmitted, independently of reproduction. On the assumption that each generation inherits (and slightly modifies) the cultural repertoire of the preceding generation, however, then differential reproductive success could still play a significant part in the differential survival and spread of cultural traits in human history. But warfare has also been an important way of increasing the frequency of some cultural traits (and decreasing the frequency of others). So a Darwinian theory of history needs to incorporate differential reproductive success and differential military success as important selective mechanisms underpinning long-term and large-scale patterns and processes in human history.3
A Darwinian theory of history would therefore claim that, within human populations, differential reproductive and/or military success increase the frequency of those cultural traits that enhance reproductive and/or military success. Within these populations, consequently, there will be persistent tendencies to increasing reproductive success (and population growth) and increasing military power.4
Having specified the selective mechanisms involved, we can go on to ask what it is that explains which traits, in particular cases, will enhance reproductive and/or military success, and that explains, therefore, why differential reproductive and/or military success lead to these cultural traits increasing in frequency and those cultural traits decreasing in frequency.
The answer suggested by the analogy with natural selection is that it is people’s relationship to their environment that plays this explanatory role for human populations, and that explains which traits will enhance reproductive and/or military success.
We therefore need to amend our formulation of a Darwinian theory of history as follows: within human populations, differential reproductive and/or military success increase the frequency of those cultural traits that, given the prevailing people-environment relationship, enhance reproductive and/or military success.
So, in any particular case, it is the prevailing people-environment relationship that explains which cultural traits will enhance reproductive and/or military success and which will not, and that therefore explains which cultural traits will increase in frequency and which will decrease. It is also the prevailing people-environment relationship that explains the extent to which the tendencies to increasing reproductive fitness and increasing military power will be realised as long-term trends.
(IV) Darwinian Historical Materialism
In order to transform this Darwinian theory of history into a Darwinian historical materialism, I need to argue that it is how people extract, process and transport resources from their environment, in other words production, that is the most important element of this people-environment relationship for historical explanations.
Production enjoys this primacy because, over the long term, variations/changes in levels of production largely explain variations/changes in reproductive and military success, for several fairly obvious reasons. More productive groups can (re)produce more people per unit area. More productive groups can, therefore, produce more warriors, can better equip, train and supply those warriors, and can sustain this in warfare for longer than less productive groups. So those groups with higher levels of production will tend to be both reproductively and militarily more successful than groups with lower levels of production.
Darwinian historical materialism would therefore claim that, within human populations, differential reproductive and/or military success increase the frequency of those cultural traits that, given the prevailing productive circumstances, enhance productive success, and thereby enhance reproductive and/or military success.
It is the existing productive circumstances (productive techniques and the knowledge necessary for their use, but also productively-relevant features of geography, climate, ecology, and so on) that explain which cultural traits will enhance production and which will not. Those traits that, in the given productive circumstances, enhance levels of production will thereby enhance reproductive and/or military success (given that variations in production largely explain variations in reproductive and military success).5 It is the prevailing productive circumstances, therefore, that explain which cultural traits will increase in frequency and which will decrease.
It is this emphasis upon the explanatory role of productive circumstances that turns a Darwinian theory of history into a Darwinian historical materialism.
As well as tendencies to increasing reproductive success and military power, therefore, Darwinian historical materialism also postulates a persistent tendency within human populations to rising levels of productive success (perhaps measured in production per capita or increasing output per unit labour input).
Whether these tendencies are realised as long-term trends depends, of course, upon the productively relevant features of the people-environment relationship, in particular the extent to which people can improve the extraction, processing and transportation of resources from their environment, given that resources are always limited, that there is often competition from other groups and populations, and that productively-relevant natural circumstances can change, sometimes rapidly and dramatically.
(V) Destructive Creation
1. Like Darwinian historical materialism, Turchin’s conception of “cultural evolution” focuses upon how societies evolve through changing frequencies of cultural traits in a population (32, 76). A cultural trait, for Turchin, is any kind of information that is passed between members of a society (77). Innovation in cultural traits may not be entirely random, but “it retains a large component of randomness for all that” (193).
Cultural traits “compete against each other… When one cultural trait increases in frequency at the expense of another, that is cultural evolution…” (226). The fate of cultural traits “ultimately depends on how well they work for the societies that adopt them” (226).
Changing frequencies of cultural traits can be an effect of both group selection and individual selection:
One of the most important insights from the theory of Cultural Multilevel Selection is that selective pressures affecting frequencies of cultural traits can work in opposite directions, depending on whether we consider selection on individuals or on social groups (81).
In what is perhaps the best chapter in the book, Turchin outlines the Price equation and how to use it to calculate the balance between individual and group selection. Given that the long-term trends that Turchin identifies (16-22, 168-71, 211-15), and which we will examine below, are produced more by group selection than by individual selection, however, then group selection would seem to be the historically predominant selective force for Turchin, at least when it comes to explaining these directional trends.
(When we switch focus away from long-term trends to relatively short-term processes, particularly, perhaps, the decline of states and empires, then Turchin’s approach would seem to emphasise the polity-disrupting effects of individual-level selection. This strikes me as a useful approach to develop, but it is not the primary focus of Ultrasociety.)
2. So, addressing the first of the two questions I posed earlier, what selective mechanisms does Turchin propose for this destructive creation? He distinguishes between group selection through direct or indirect competition (83), and says that
… tribes may compete indirectly. For example, the environment could be so harsh that any group might be hit by a total catastrophe (famine, drought, or flood) and wiped out. However, tribes with more cooperators are more resilient and have a better chance of surviving such a calamity. Survivors then repopulate the landscape, replacing the extinct tribe, until the next disaster hits (83, my emphases).
So indirect competition seems to involve differential survival and/or reproductive success. (And what could “more resilient” mean in this context, other than that the relevant “tribes” better maintain some form of production. So here, in a situation reminiscent of the “harsh environment” of the Pleistocene (214), differential survival and reproduction are perhaps largely explained through differential productive success.)
Turning to direct competition, group selection here can take place in several ways, though most of them involve warfare (42, 83, 116-7), defined as violence between human groups or societies (213).
The most extreme form of group selection, “genocide”, leads to the elimination within a territory of the losing groups and their culture, and their replacement by the victors and their cultural traits (116). Territorial acquisition presumably does not require the total elimination of the defeated group. Some would be killed, but some would be dispersed into other groups, into which they would assimilate (113).
A second form of group selection, “ethnocide” or “culturecide”, involves the forcible assimilation of people into a victorious culture, its language, religion, social norms, institutions, and so on (116-7).
A third form is “assimilation”, the gradual (and presumably non-forcible) destruction of the cultural traits of the losers, and their adoption of the cultures of the victors (117).
Finally, there is “imitation” of the more successful by the less successful. This latter form of direct competition is the only one that does not involve war (117).
The upshot is of these processes is the differential survival of cultural traits:
What all these scenarios have in common is that the cultural traits of successful societies spread at the expense of the traits of the less successful. Everything from brutal genocide to the peaceful and voluntary adoption of institutions serves the process. The ‘destructive’ part need not result in people being killed. What need to be destroyed are those cultural traits that make societies less successful – less cooperative, less internally peaceful, and less wealthy (117-18).
Selection has been getting gentler, but Turchin concludes his survey of the different modes of “cultural group selection” (116) by saying that “throughout the vastness of human history, it has been the brutal forms of between-group selection that have predominated” (118).
As we shall see, what Turchin really thinks is that over most of “the vastness of history” (that is, during the later Pleistocene), indirect competition has predominated (214, 215). Nevertheless, it is clear that, over most of the last 10,000 years, the period with which he is primarily concerned, Turchin prioritises direct over indirect competition. It is also clear that, of these brutal to peaceful alternative forms of direct competition, he sees warfare as the predominant form in this period, and thus the most important selective mechanism (as the sub-title of Ultrasociety suggests). And not just warfare, but warfare at its most destructive. Turchin says that the evolution of large, complex societies is
only possible when societies compete against each other so that those lacking the right institutions fail. The costly institutions of complex societies manage to spread and propagate because the societies that possess them destroy those that don’t (19-20, my emphasis).
So Turchin’s theory of destructive creation (23-44) is a Darwinian theory of history that emphasises warfare as the predominant (group) selective mechanism for most of the last 10,000 years.
As well as larger societies, warfare also created more cooperative societies. Cooperation and warfare are “seemingly contradictory, yet mutually interdependent forces” (36), because warfare selects for more cooperation within societies by eliminating less cooperative societies:
Societies can compete in many ways, but until quite recently the main – and the most demanding – way has been war. Just as economic competition eliminates the less efficient businesses, military competition in history eliminated less cooperative societies… By eliminating poorly coordinated, uncooperative, and dysfunctional states it [war] creates more cooperative, more peaceful, and more affluent ones (42, my emphases).
Cooperation tends to be easier among small societies made up of family and friends (36-7), and the difficulties of cooperation in large-scale societies of strangers means that such societies are fragile (37). Nevertheless, over the long run, many durable small-scale societies were replaced by a few large-scale, if fragile, societies (38). And large societies that were less cooperative were “weeded out” (40) by large societies that were more cooperative.
This tension of warfare selecting both for more cooperative societies and for larger societies that tend to be less cooperative is resolved by the development of appropriate institutions and (generally religious) ideologies that suppress internal violence and encourage cooperation (40, 44).
(The word “cooperation” has a positive ring to it. But cooperation is, or leads to, organisation, and organisation can be oppressive and exploitative, as it seems to have been, according to Turchin, during the “despotic” interludes of chiefdoms and archaic states.)
So, Turchin sums up,
it was competition between groups, usually taking the form of warfare, that transformed humanity from small-scale foraging bands and farming villages into huge societies with elaborate governance institutions and complex and highly productive economic life (44; see also 22).
3. Turning now to the second of the two crucial questions that I identified earlier. Turchin does not explicitly ask what it is that explains why selection selects this cultural trait rather than that cultural trait, but he does emphasise the effect upon warfare (his primary selective mechanism for the last 10,000 years) of different terrains and of breakthroughs in military technology.
Turchin makes various suggestions on this topic, at various places in the book, without ever really attempting to synthesise them into a clear statement. (Of course, the various reasons that terrain and military breakthroughs affect warfare do not have to connect - although a clearer statement of them would have been useful.) Let’s begin, then, with some of the distinctions that he makes.
Turchin distinguishes between war within societies (“internal” war) and war between societies (“external” war). The former is merely destructive, whereas the latter can be creatively destructive (116). This is presumably because there is more likely to be greater variation in cultural traits between groups involved in “external” warfare (118, 119), so such warfare is more likely to lead to changes in the frequencies of cultural traits within a population - cultural evolution - than is internal warfare.
The important role of terrain in warfare is “relatively uncontroversial” among military historians, and it seems to be differences in kinds of terrain that explain the changing balance between internal and external warfare (120). Turchin here adopts a distinction seemingly made by historical linguists, between spread zones and residual zones:
Historical linguists call areas in which languages of various families are preserved ‘residual zones.’ A ‘spread zone,’ by contrast, is an area where languages tend to spread out widely, driving previous languages in the area to extinction. The typical result of a spread is that only one language occupies most or all of the area. Spread zones are therefore regions where competition between cultural groups is so intense that one group can drive many others to (cultural) extinction over a large area (119).
Tropical forests and mountain regions are residual zones, and therefore are regions of high linguistic diversity. Examples of such residual zones would include New Guinea (which has both tropical forest and mountain regions), the uplands of south-east Asia, and the Caucasus mountains (119).
Spread zones include broad, treeless flatlands, such as the Great Eurasian Steppe between Ukraine and Mongolia, or the North American Great Plains. Spread zones lead to the extinction of some languages, and thus low linguistic diversity (119).
Warfare in the open terrain of spread zones is more likely to be external warfare, involving more cultural variation, leading to intense selection, and therefore more cultural evolution, than is warfare in the difficult terrain of residual zones (119).
Presumably because of the difficulties of long-distance warfare in forested and mountainous regions, the terrain in residual zones inhibits external warfare between culturally-dissimilar groups, but allows internal warfare between culturally-similar groups, among which there is little or no between-group variation. The result is little or no cultural evolution, but more diversity within the population of the residual zone taken as a whole, as in New Guinea (119).
Revolutions in military technology have also had a decisive effect on human history, Turchin says, particularly those innovations that shifted the advantage from defensive to offensive warfare (130):
Clearly, the killing power of human weapons has grown astronomically from the Stone Age to the Atomic Age. Such dramatic technological transformations had to have an effect on social evolution.
And they did. There were several periods of history when war-making capacity increased by leaps and bounds… Of particular interest are the innovations that shifted the advantage from defence to offence (130).
Armour and hand-wielded weapons were important, but long-range weapons and mobility “make offensive war more devastating, and therefore a more potent force of social evolution” (130):
In terrain where they have room to maneuver, mounted archers have a huge advantage over infantry wielding short-range weapons such as spears and swords (128).
The greatest empires in history depended upon these military breakthroughs (130). With hand-held (non-ranged) weapons only part of the army can engage at any one time. Nevertheless, assuming that both sides have similar hand-held weapons, the side with the greatest numbers will tend to win (158). But projectile weapons on flat plains allow concentrated fire by whole armies, so the advantage of greater numbers is magnified, and selective pressure is greater (157-8):
So there is an intense selection pressure for cultural groups living in flat terrain to scale up, and a very high price to pay by those that fail to do so (recall where the first states emerged). In the mountains the selection pressure for larger societies is reduced considerably (158).
So, it is not just terrain that decides whether warfare is creative, it is also innovations in military technology that enhance range and mobility, and give offensive war the advantage over defensive warfare. If offensive warfare has the advantage, then group selection is intensified. So those military breakthroughs that shift the balance in favour of offensive warfare are more likely to lead to intense selection and cultural evolution than those that favour defensive warfare (130).
To attempt a partial synthesis of Turchin’s ideas here: breakthroughs in military technology that advantage offensive warfare (such as long-range weapons and greater mobility) are likely to lead to more intense warfare. In open terrain (spread zones) this is more likely to involve external warfare against culturally dissimilar groups than in difficult terrain (residual zones), and this external warfare, with greater cultural variation between groups, is more likely to lead to more rapid cultural evolution. So variations in terrain and changes in military technology explain variations and changes in the intensity of warfare, and therefore in the rate of cultural evolution.
(VI) Some Criticisms of Destructive Creation
1. So, in this military competition, larger polities have an advantage over smaller polities, and more cooperative polities have an advantage over less cooperative polities. This results, over the long term, in the average polity becoming larger and more internally cooperative.
But is military competition the only selective mechanism at play here? Is there no role for differential reproductive success? According to Turchin,
A… promising route to victory is to bring more warriors to the conflict… A polity could breed more warriors, but that’s a slow process. Or it could form an alliance with other polities, radically and rapidly increasing the size of the allied army (156-7).
So Turchin is dismissive of the notion that enhanced reproductive success can confer significant benefits in warfare through the breeding of more warriors because, in the selective context of warfare over most of the last 10,000 years, it is too slow a process compared to increasing the size of the army by forming alliances.
Given that he dismisses polity growth through higher reproductive success (and, therefore, selection for polity growth through differential reproductive success) as such a “slow process” compared to “radically and rapidly” growing through alliances, Turchin must regard differential reproductive success as playing little or no significant part in the growth of polities over most of the last 10,000 years, either through its effect on differential military success or, presumably, independently of differential military success.
And, confirming this interpretation of Turchin’s views, none of the explanations he suggests for historical changes over the last 10,000 years, as we shall see, invoke differential reproductive success (with one very significant exception).
Of course, Turchin acknowledges that global population growth has taken place over the long run, as when he points out that the chance of any individual suffering a violent death has diminished because the growth of the number of casualties in the wars of the modern era has not kept pace with the growth of populations (41).
But Turchin’s group selection through military competition does not seem to favour the expansion of the more reproductively successful, and so generates little or no tendency to higher reproductive success. It is difficult to see, therefore, how destructive creation would explain the trend to increasing reproductive success and accelerating population growth over most of the last 10,000 years.
2. Nor does this selection through warfare favour the more productive polities. Turchin is dismissive of differences in productive technology as contributing to differences in military success, at least for most of the period he is primarily concerned with:
There are many methods by which a polity can improve its chances in military conflict. One is to manufacture better weapons or armor. But technological evolution in prehistory was so glacially slow that both sides in a conflict would quickly exhaust the stocks of available technology that could give them the edge against the enemy. Any new technological breakthrough was rapidly adopted by all groups, and none gained more than a temporary advantage from it (156).
Turchin (28, 156) says that the Asian War Complex, the use of a composite bow (a ranged weapon) and body armour, was just such a short-lived advantage, spreading quickly through North America.
Now, if “any new technological breakthrough was rapidly adopted by all groups, and none gained more than a temporary advantage from it”, then between-group variation in productive technology would quickly be eliminated by this diffusion.
Turchin himself stresses the importance of between-group variation for selection (89-90, 93-4). The left-hand side of the Price equation, after all, “contains the ratio of between-group variance to within-group variance” (87). The lower this ratio, the less powerful is between-group selection.
So, with variations in productive technology quickly eliminated by diffusion, there would be little or no selection for improved productive technology. The improvements in productive (and destructive) technology that have taken place over the last 10,000 years would seem, therefore, to be unexplained by the group selection process that Turchin suggests, and presumably must be explained by some other process (such as, for example, the rational choice of more effective technologies).
For technological innovations to be selected and spread, they need to enhance the fitness of some units of selection, there have to be differences in selective outcomes (for Turchin, that would be differences in military success) that are explained by between-unit differences in technology. But, given what Turchin (156) says here, there would seem to be little or no role for differential productive success in explaining differential military success.
And if every “technological breakthrough” rapidly diffused, then how did warfare select for “highly productive” economies (44), and, therefore, “wealthy” (23, 118) and “affluent” (40, 42) societies? It is not, after all, just polity growth that Turchin is claiming to explain here.
Turchin obviously acknowledges the long-term trend to productive development (44), but how does he explain it? Destructive creation may generate tendencies towards larger and even more peaceful polities. But how, as Turchin expounds it here, does it generate tendencies towards more productive economies? And under what conditions are these tendencies realised as historical trends?
Turchin asserts that “the killing power of human weapons has grown astronomically” (130), and he wants to stress the effect of this upon cultural evolution (130). But how does destructive creation explain this astronomical growth in the destructive power of military technology, if there is little or no selection for breakthroughs in military technologies?
If improvements in military technology would diffuse so rapidly, quickly eliminating any advantage conferred by them, then how could these improvements be as selectively crucial as Turchin claims elsewhere (130)? Any advantage of offensive warfare conferred by long-range weapons and mobility would presumably quickly disappear, and warfare would then reduce in intensity.
And if the diffusion of technological innovations was so fast and so widespread (“rapidly adopted by all groups”), then why would not the same be true of non-technological cultural traits? Wouldn’t this lead to the kind of situation Turchin describes in New Guinea, in which there “was very little variation in their [clan’s] cultural characteristics and therefore very little evolution”, even though selection through clan warfare “was very strong” (119)?
Whatever Turchin says when generalising, however, it is worth noting that, as we shall see, many of his explanations of particular historical processes, while ignoring differential reproductive success, actually seem to implicitly invoke differential productive success.
Moreover, Turchin effectively contradicts this general dismissal of the selective effects of (innovations in) productive technology in another generalisation. He claims that “it is logistics that determine whether one society will prevail over another in the long run” (198). So Turchin is saying that, over the long run, differential logistical success explains differential military success.
Military logistics involve the movement of troops, and their supply with equipment, food, and so on (198). There seems, then, to be no exclusive distinction between production and logistics; logistics are simply the militarily-relevant aspect of production, of the extraction, processing and transportation of resources. So I would locate “logistical success” within a more general productive success.
But Turchin does not incorporate this insight into his theory. Indeed, in dismissing the military effect of technological innovations (156), he effectively contradicts it (given that these “technological breakthroughs” might include breakthroughs in logistical technologies).
Incidentally, if logistics, the militarily-relevant aspect of production, do play this crucial role, then it is (as Darwinian historical materialism argues) productive circumstances that explain which innovations will (directly or indirectly) enhance logistical success, and thereby military success, and so increase in frequency (or not do these things, and so decrease in frequency).
I have long argued for a Darwinian perspective on human history (Nolan, 1993, 2002a, 2002b, 2003, 2006, 2009), so there is much in this book that I agree with. Turchin’s work on the growth in the size of polities, on increasing cooperation within these polities, and how these relate to long term changes in different forms of violence, is valuable, and certainly merits further research. But I would suggest two important qualifications to destructive creation’s approach to selective mechanisms as Turchin presents it. I would integrate differential reproductive success into any account of the last 10,000 years (both as an independent selective mechanism and as an influence on differential military success). And I would argue that differential productive success, while not a selective mechanism as such, is a crucial part of any explanation of both differential reproductive success and differential military success.
3. Darwinian historical materialism emphasises the role of variations in productive success in explaining variations in reproductive success. In turn, differential reproductive success increases the frequency of those traits that (in the prevailing productive circumstances) enhance productive success. It is because of this “dialectic” of production and reproduction that there are persistent tendencies to productive development and population growth.
In turn, variations in productive and reproductive success together explain variations in military success. To paraphrase Cicero, it is production and reproduction that provide the “sinews of war”, the warriors and the weaponry to wage war (not to mention the food and other supplies for those warriors). Differential military success then increases the frequency of those traits that enhance productive success and (therefore) reproductive success. And it is because of this “dialectic” of production, reproduction and warfare that there is a persistent tendency to increasing military power, as well as the persistent tendencies to productive development and population growth.
Turchin is unable to make these connections, at least with any consistency. As I have said above, and just to be absolutely clear, I am not suggesting that Turchin is not aware of, or does not acknowledge, the enormous population growth and the productive development of the last 10,000 years. He is clearly aware of both of these (41, 44). The issue, however, is whether his theory of destructive creation, as he expounds it, can explain them, and explain them by connecting them in this way. Given that he is so dismissive about innovations in productive technology explaining differences in military success (156), so dismissive, therefore, of military selection for improved productive technology; and given that he is so dismissive of military selection through differential reproductive success (156-7), and, therefore, for higher reproductive success; then his general theory seems to provide no way of explaining either productive development or population growth, still less of explaining them in any connected way.
Perhaps Turchin could explain population growth and the expansion of people across the globe as a by-product of productive development; but he has already dismissed differential productive success as a significant historical force. So the improvements in productive technology, and therefore the rises in reproductive fitness (and the population growth), that have taken place over the long term in human history are effectively unexplained by the group selection process that Turchin proposes.
For Darwinian historical materialism, it is fairly clear why less productive polities would be at a selective disadvantage, having fewer people (and therefore fewer warriors), less developed and/or fewer weapons, and so on. But what selective forces, in Turchin’s theoretical framework, are going to lead to the decline of less productive polities if there is no selection for improved reproductive success or for superior technologies?
Turchin frequently employs language that implies a process of (more or less) rational choice of cultural innovations, rather than one of selection of (more or less) random cultural innovations. (Examples of such language can be found on pages 38, 67, 93, 173, 174 and 200.) And in his dismissal of “technological breakthroughs” and of a “breed more warriors” strategy, Turchin’s (156-7) language implies a process of rational choice in the face of an imminent threat. As if it was a matter of saying “We’re at war, so let’s breed more warriors and develop better (military) technologies”, rather than a process of random innovation and subsequent selection through differential military success. This perhaps makes it easier for him to dismiss explanations through differential reproductive success and differential productive success because, if the former is such “a slow process” and the latter is “glacially slow” (156), then, at the point of war, it is rather late to decide to breed more warriors, to develop better weapons, and to produce more of them.
I am sceptical of the use of rational choice to explain long-term processes and large-scale patterns in human history. And historical selection is not, anyway, a process that relies upon people knowing which innovations would be the most fitness-enhancing, and having both the interest in and the power to adopt those innovations; it is not a process dependent upon such rational choices and favourable social structures. This is why Darwinian historical materialism argues that, when subject to selection through military competition, it is those polities that happen to have higher levels of production (and therefore larger populations and more and/or superior military technology) that will tend to be militarily successful against those that happen to have lower levels of production (and therefore smaller populations and less and/or inferior military technology).
4. Diffusion’s effect in reducing between-group variation raises another issue. The diffusion of technology or other cultural traits is connected to Turchin’s “gentler form of cultural selection… imitation” (117). Imitation, after all, results in the (peaceful) diffusion of technologies and other cultural traits.
Now, Turchin points out that
Even small amounts of migration can destroy variation rapidly, and in most animal species migration can be quite substantial…
Early proponents of group selection did not understand the importance of variation between groups, nor how difficult it is to maintain in the face of constant migration (90).
Migrating people, however, tend to assimilate to the new culture (or their children do) (93). But human beings can spread cultural traits between groups through imitation, with or without migrations of people, and a diffusion of cultural traits is the result, as Turchin effectively accepts (89-90, 93-4).
So diffusion is a “migration” of cultural traits, and is a consequence of imitation. And perhaps, like migration, even “a small amount” of imitation/diffusion can “destroy variation rapidly” (90). Turchin’s “imitation” cannot, therefore, be part of a selective mechanism for historical change (which is not to say, of course, that it doesn’t happen). To the extent that (successful) imitation/diffusion is common, and between-group variation is reduced, then there is less of a selective process.
But perhaps there are reasons to think that imitation/diffusion (at least successful imitation/diffusion) is not all that common, and not all that rapid; reasons that Turchin himself effectively points out. As far as the receiving society is concerned, diffused traits are, effectively, innovations. Like other innovations, they need to be accepted by the “society at large” (193). Some of them may also need “vital [bureaucratic and religious] institutions” (19) if they are to succeed. Those institutions are “all costly” (19), and also need time to develop (160-1). This difficulty of developing appropriate “cultural mechanisms” to cope with innovations is perhaps why history “is littered with corpses of failed states and empires” (39).
Or perhaps the relevant innovations have unpleasant side-effects that would inhibit their imitation/diffusion. As we shall see, this may have been the case for the innovations involved in transitions to farming (173, 174).
And perhaps some successful imitations/diffusions depended upon productive circumstances. After all, horse-riding and horse-archery did not seem to diffuse so rapidly as to prevent nomad success, perhaps because the extensive grasslands necessary for rearing large numbers of horses did not exist in the farming regions adjoining the steppes, as Turchin (200) himself acknowledges. So differences in the environmental underpinnings of different productive techniques might prevent a rapid imitation/diffusion of a “technological breakthrough”.
So, for all of these reasons, the successful imitation/diffusion of technological innovations may not have been as fast and widespread as Turchin (156) suggests (and not, therefore, be as threatening to a selective theory of history).6
5. So, when generalising, at least for most of the last 10,000 years, Turchin (19-20, 42) places virtually all of his emphasis upon warfare as the selective mechanism, with little or no place for differential reproductive success, not even for differential reproductive success as (part of) the explanation of differential military success (156-7).
Identifying warfare as the “specific evolutionary mechanism” in explaining the development of “larger societies” and “big states” (156) is all very well. But, as I have pointed out (sections II, III and IV), a selective explanation needs more than a selective mechanism.
Just because war is the main selective force, that does not entail that warfare also explains what it is that will be selected. It may seem obvious that larger and more cooperative groups tend to be militarily more successful than smaller, less cooperative groups, but the context of selection is crucial here. The mechanism of military competition may allow Turchin to infer persistent tendencies to larger polities and to increased cooperation within those polities, but in itself it gives no indication as to whether those tendencies will be realised as long-term historical trends. What war actually selects, even whether it actually selects for larger polities, depends upon the context. The mechanism alone will not explain how far this process will go or how fast the process of change will be. Moreover, it does not in itself explain which other traits are selected.
These tendencies (and anything else that selection through warfare might explain) depend upon the people-environment relationship (and particularly productive circumstances) for their realisation as historical trends.
Intense warfare within a Holocene foraging population might have resulted in that population making a transition to agriculture. But intense warfare within a Pleistocene foraging population might simply have maintained efficient foraging. It depends upon the productive circumstances.
To explain what selective processes actually select, we need to examine the people-environment relationship (just as, with natural selection, the organism-environment relationship played this part), particularly the prevailing productive circumstances. Not only will this help us to explain why trends to larger polities and increasing cooperation occur when they do occur (and why they do not occur when they do not), but it may also help us to explain the spread of other cultural traits.
Turchin does, after all, say that “different world regions took quite different paths” (76). What will allow us to explain these “quite different paths” is information about the particular people-environment relationships in particular regions, especially information about their particular productive circumstances.
But Turchin does not seem to see that a crucial element, a “necessary condition” if you like, of a selective explanation (whatever the selection mechanism) is the specification of what it is that explains why this trait rather than that trait is actually selected. Consequently, he pays virtually no attention to the people-environment relationship that selection works within, except in so far as it affects warfare.
Moreover, different terrains and breakthroughs in military technology seem, in Turchin’s account, only to affect the intensity of selection through warfare, rather than explain what it is that is selected. More intense warfare (between culturally dissimilar groups) simply selects larger and more cooperative (albeit sometimes more despotic) societies somewhat more rapidly than less intense warfare. Warfare does not, according to Turchin’s general theory, select for more productive or reproductively successful groups, and he tells us little about explaining these “quite different paths” that people in different regions have taken. (Turchin’s explanation of the transitions to agriculture, as we shall see, largely ignores regional differences in productive circumstances, and so tells us little about why agriculture developed in some places but not in others, or more rapidly in some places than in others.)
So Turchin’s equivalent of my second question just seems to be “When is selection more or less intense?” And, in so far as he offers an answer to that question (terrain, military breakthroughs), that answer applies only when warfare is the main selective force, which he says is true only of the last 10,000 years or so of human history (with the increasing exception, as we shall see, of the last 2,500 years, and especially of the last 500 years).
6. Turchin’s virtual ignoring of the people-environment relationship sometimes emerges fairly clearly:
It isn’t human desire that determines whether an idea can work. It needs to be accepted by other people, the society at large, for an inspiration to turn into technology (193).
But it is not just “society at large” that “determines whether an idea can work”, it is, ultimately, the natural context too (and perhaps not all that ultimately for innovations in productive technologies). Or, rather, it is the people-environment relationship (especially the elements of that relationship implicated in production) that ultimately explains whether an innovation does or does not enhance reproductive or military fitness. Innovations that spread do so because they are more effective in enhancing reproductive and/or military fitness, largely because they enhance production in the given productive context. Other innovations that do not work as well, in the given productive circumstances, will not spread so successfully (though they may have worked better in different productive circumstances).
Of course, the selective mechanism (such as military competition) and the relevant circumstances (such as an intensifiable agriculture) are both “necessary conditions” (19) for a selective explanation of cultural evolution. But describing them both as necessary conditions is not really a useful way of formulating the issue. We need to place both of them into a clear explanatory structure, and I think that Darwinian historical materialism does just that: differential reproductive and/or military success select for those cultural traits that, because they enhance productive success in the given productive circumstances, enhance reproductive and/or military success; so the given productive circumstances explain which cultural traits enhance productive success, and thereby enhance reproductive and/or military success, and therefore increase in frequency.
Turchin and I perhaps have somewhat different conceptions of what needs to be explained in human history. For Turchin it is primarily the growth of polities and changes in levels of cooperation and of violence, and secondarily the development of higher levels of production (23, 40, 42, 44, 118, 130). I acknowledge these trends and changes, and I have long argued that military competition helps to explain long-term trends in human history (Nolan, 2009). For me, however, the crucial historical trends have been productive development, population growth, and growing per capita military power, none of which the theory that Turchin offers (when generalising about history) can explain.
(VII) Turchin’s Outline of History
1. It might seem implausible that a Darwinist would propose a theory of history that does not explain (and largely ignores) the increasing reproductive success and population growth of the last 10,000 years, and also does not explain the productive development that made that reproductive success and population growth possible. But Turchin (16-22, 168-71, 211-15) presents an outline of history over that period in which the main historical trends are not population growth and productive development, but the increasing size of polities, increasing levels of cooperation within these polities (the “obverse” of which is falling rates of internal violence), and rising then falling levels of warfare. So the account I have given of his general theory of history seems to be accurate (although, as we shall see in later sections, Turchin’s explanations of particular historical processes are often effectively inconsistent with his general theory).
Although Turchin (76) criticises “stadial” theories of history, he himself effectively presents a stadial account of this development of increasingly large polities over the course of human history (defining a polity as “an independent political unit that makes its own decisions about matters of peace and war” (16, 139)).
Anatomically modern humans had evolved by 200,000 years ago (14), and humans have spent 95% of the time since then living in small-scale, impermanent foraging bands numbered in the tens (5, 14, 16). Though effectively independent polities, these bands were embedded within “tribes”, numbering in the hundreds or a few thousand, say between 500 and 2,000 people. These tribes were ethnolinguistic groups “sharing the same language and culture and united by a common identity” (5, 12).
But, after the Pleistocene gave way to the Holocene interglacial, and especially over the last 10,000 years or so, human polities have developed an ever-increasing scale of cooperation (16, 140). Things began to change between 12,000 and 10,000 years ago as the first farming villages developed. These were a new kind of polity that typically numbered in the hundreds (14, 16).
The first centralised polities, simple chiefdoms, developed from around 7,500 years ago. Simple chiefdoms were made up of many farming villages ruled by a hereditary chief, and they typically numbered in the thousands (16).
Not much later, from around 7,000 years ago, complex chiefdoms developed. Complex chiefdoms differed from simple chiefdoms in that they typically had a three-tiered administrative hierarchy with a paramount chief governing several subordinate chiefs, each of whom controlled several villages. Complex chiefdoms standardly numbered in the tens of thousands (16).
From around 5,000 years ago, even more centralised polities developed, archaic states with cities as centres of political power, and with populations typically numbering in the hundreds of thousands. And from around 4,500 years ago, what Turchin calls macrostates developed, with populations numbered in millions (16).
As the scale of human polities continued to increase, mega-empires developed from around 2,500 years ago, numbering in the tens of millions (16, 17).
From around 200 years ago, huge nation-states developed, with populations in the hundreds of millions (16). And, in perhaps an early sign that human polities are moving beyond the nation-state, there has been significant international cooperation since the mid-twentieth century (5).
As this growth in the size of polities occurred, there were changes in levels of both cooperation and inequality within polities, and in rates of violence within and between polities, as measured by changes in the probability of an individual being killed by violence (215). Because they have different causes (216), however, these different kinds of violence have different historical trajectories (215).
2. As humans evolved, and then as human cultures developed, there were shifts backwards and forwards between more and less inequality, from hierarchical primate groups, to egalitarian foragers, to despotic archaic states, to constitutional democracies (211-12). These changes were connected to changes in rates of internal violence within polities (215-6).
The Great Apes live in hierarchical societies, often dominated by alpha males (211, 254 n. 184), but early humans suppressed alpha males, and foraging societies tended to be cooperative and egalitarian. Social position was based upon age, gender and reputation, and leaders led by persuasion and example (21, 211).
Rates of homicide, individual-on-individual violence rather than group violence, seem to have been relatively high among foragers, for whom around half of lethal violence was individual-on-individual violence rather than warfare. Some of this individual violence may have involved defending equality against those who perhaps had some small degree of power, and wanted to acquire more (215, 216). After its high point among foragers, however, rates of individual violence then gradually declined, although not in a linear fashion (216).
This egalitarianism persisted until, and even beyond, the development of agriculture (135-6, 211). From around 10,000 years ago, though, there was a reversal of the egalitarian trend (22).
The first centralised polities, chiefdoms, allowed alpha males to rise again as chiefs (211). In archaic states, alpha males reappeared as god-kings, along with severe oppression, slavery and human sacrifice (22). Archaic states gave elites massive power over commoners, and were perhaps the most despotic societies that have ever existed (211). Within these archaic states, the internal violence of despotism defended inequality against commoners (215).
As we have seen, mega-empires, made up of millions of people, developed in the first millennium BCE. This “Axial Age” began a turn away from despotism (212), as human sacrifices and deified rulers disappeared (22). An expanding circle of cooperation developed, beyond single ethnolinguistic groups. New ideologies, generally religious and involving “Big Gods”, reinforced people’s capacity for cooperation, and increased trust in these huge, anonymous groups (212).
Over the past 10,000 years, therefore, rates of violence by the powerful against the powerless (slaves, serfs, women, ethnic and religious minorities, outcasts) probably increased until the first millennium BCE, and then declined. This was not, of course, a simple linear decline (215-6).
This increase in the scale of cooperation has been the “single cause” (218) of the decline in the probability of death by violence since its peak during the development of archaic states. Peace requires managing, and the expanding ultrasocieties of the last 10,000 years covered an increasing proportion of the population, and have developed more effective institutions to preserve internal peace (218).
But these institutions need to be buttressed by moral values, so new values developed along with these changes. Values of helping relatives and friends may work for small-scale societies, but large-scale societies need values against nepotism and cronyism. So there has been a coevolution of institutions and values (218).
During the modern period, from the European Enlightenment, this reduction of inequality continued, and even accelerated: the abolition of slavery and serfdom, the ending of aristocratic legal privileges, the rights revolution, the spread of democracy, the welfare state, and the equal treatment of women and minorities (22, 212). The expanding circle of cooperation now involves most of humanity (212).
3. But it is between-group violence, warfare, that is central in Turchin’s account of human history. The rate of deaths that were a result of inter-group violence measures the level of warfare; the higher this death rate, the higher the level of warfare (41, 171).
At the most general level, there has been an A-shaped curve of war over the last 10,000 years, in which the probability of dying as a result of war initially rose as populations grew and agriculture developed (169, 171). Only when even larger societies developed did the incidence of warfare, and the probability of being killed in war, begin to decline, although in an uneven rather than a linear decline (215).
To be more specific, between the development of agriculture and the development of states, as societies became increasingly centralised, levels of warfare rose (169, 215). Rates of death through warfare peaked with the intense warfare of “late pre-state” and “early state” farming polities. After the rise of large-scale polities (presumably from the rise of macrostates) the probability of dying in war trended downward, and continued to decline over the long term (169, 171).
Of course, as polities became larger and more cohesive, wars became larger-scale and more destructive. But Turchin explains the declining rate of death in inter-polity warfare partly through the wars of larger polities (states and empires) becoming frontier wars, not wars near the centre of the polity, so an increasing proportion of people lived peacefully (40-1):
For the average citizen, the probability of dying in a war declined as political units became larger (218).
(Perhaps what Turchin should have said here is that “the probability of dying in war” at first increased as political units became larger (growing from bands into villages, then chiefdoms), and only declined after warfare reached a peak with “late pre-state” and “early state” farming polities (169, 171, 215).)
Moreover, over the last 10,000 years, the violence of warfare decreased because populations increased more (218-9). Absolute casualties grew, but decreased in relative terms.
So there is a seeming paradox that war drove the evolution of larger polities, and larger polities made violence decline (219).
4. Turchin’s (140) picture of human history over the last 10,000 years, then, is essentially focused on the growth of polity size because of military competition. Other directional trends (increasing internal cooperation, falling individual violence, rising then falling external warfare, and the rising then falling internal violence of centralized hierarchies) are largely explained by that central process.
But it is important to understand that, for Turchin, this increasing size of polities is not about increasing reproductive success and population growth (at least, not after transitions to agriculture). The populations of his polities grow but, as we shall see, the growth in the size of polities is generally presented as a result of alliances and/or conquests, with little role for differential reproductive success or, therefore, population growth in this increase in polity size (with the only significant exception in the last 10,000 years being transitions to agriculture).
On the basis of Turchin’s general theory, there is no reason to expect regional or world populations to grow, or the populations of his polities to get any denser as the polities grow larger. For all his theory of destructive creation tells us, Turchin could be describing a constant population of one billion human beings divided into one hundred million bands of around ten people each, then ten million villages of around one hundred people each, and so on, up to ten nation-states of around one hundred million people each. Nothing in Turchin’s general theory contradicts this possibility.
(VIII) Hunter-Gatherers in the Pleistocene
1. Most of human history has been spent during the climate oscillations between long glacials and short interglacials of the later Pleistocene, the geological epoch that ended around 12,000 years ago. At the height of the glacials, glaciers could cover one-third of the Earth’s surface. As the earth passed from glacial to interglacial, sea levels rose, then fell as the interglacial gave way to another glacial (91). These conditions had profound consequences for human groups:
The climatic chaos of the Pleistocene, the geological epoch that began 2.6 million years ago and lasted until 10,000 BCE, did not permit any sustained population growth of early human groups. There must have been sporadic conflict leading to violence between small bands of foragers…
The overall level of intergroup violence was low [during the Pleistocene] because there was plenty of unoccupied space to retreat to when threatened – or for that matter, to occupy instead of fighting your neighbours for their land (214-5).
Elsewhere Turchin says that
during the climate chaos of the Pleistocene, warfare was probably rare. Human populations were in much greater danger of being wiped out by the advancing glaciers than by another foraging band (169).
So warfare was “rare” and “sporadic” during the Pleistocene because population density was so low. Turchin (169, 214) must therefore think that warfare was relatively unimportant as a selective force over the long glacial periods of the Pleistocene, that is over most of human history (and, indeed, during the evolution of “modern” humans).
During this period of Pleistocene “climate chaos”, the harsh climate was the main danger that people faced (169), and Turchin argues that “the main agent of selection between groups must have been the harsh environment” (214). But environments, no matter how harsh, do not, of themselves, change the frequencies of cultural traits, and thus are not “agents of selection”, as Turchin effectively recognises:
Groups that solved collective-action problems, such as hunting large prey, defending against dangerous predators, coping with scarcity, thrived – or at least hung on… Bands that failed to sustain cooperation, or to preserve their cultural store of information, went extinct. During the Pleistocene, then, competition between human societies was usually not direct. Successful groups grew in size, split into daughter groups, and colonized areas where unsuccessful ones had gone extinct (214, my emphases).
As we have already seen, Turchin (83) describes selection through indirect competition in a harsh environment (though without mentioning the Pleistocene), and he emphasises the differential survival and reproduction of those bands that were “wiped out” by an environmental catastrophe as against those that were “resilient”, survived the catastrophe, and went on to “repopulate the landscape”.
So between-group competition over most of human history has been indirect competition, and the success criteria were survival and reproduction. Differential survival and reproductive success must, then, have been the crucial selective mechanisms. In the virtual absence of warfare, these standard Darwinian mechanisms must have been the main “agents of selection”.
And such selection would not sustain just any form of cooperation. There would be selection for forms of cooperation that enhanced survival and/or reproduction in the prevailing circumstances. And, given that two of these three “collective-action problems” (214) that Turchin mentions involve production (and the other involves the production of weapons), the appropriate form of cooperation would surely be that which, given their existing productive circumstances, enhanced production.
During the later Pleistocene, modern humans developed improved projectile weapons for hunting: slings allowed rocks to be thrown faster and farther, spearthrowers (atlatls) did the same for spears. Bows were developed in southern Africa from around 70,000 years ago, becoming more sophisticated and lethal over time (96, 101). These weapons were developed during the Pleistocene when, according to Turchin, competition between groups was usually indirect, and warfare was “rare” or “sporadic” (169, 214, 215). These improved hunting weapons gave early humans advantages against large predators, and against occasional alpha males (129), but were “needed primarily for food” (214). These weapons spread, therefore, because, in the prevailing productive circumstances, they enhanced production. So the “human way of war”, relying upon striking from a distance (129), seems to have developed out of the human way of hunting, out of production.
Turchin paints his account of human history with a very broad brush, which is entirely appropriate given that his main purpose is to explain the main trends of history (I do the same thing elsewhere on this website). But it is perhaps worth mentioning that it has long been apparent that group size during the later Pleistocene may have varied significantly. So, for example, seasonal changes in productive circumstances, such as the gathering of large herds or runs of fish, may have selected for seasonal changes in group size, say from small bands to much larger “tribes”, with appropriate changes in social structures and behaviours (see, for example, Pettitt, 2005, 163). (This phenomenon is also well established among ethnographically-known groups.)
2. During the Pleistocene interglacials, the short periods of relatively stable climate, populations would expand, conflicts would develop, war would spread, and pacifist groups would have been eliminated (169). So a change in productive circumstances (consequent upon climate change) led to population growth and increased warfare.
I think it is also likely that, as well as “direct” selection against the less-warlike groups, there would have been selection against the less productively successful groups during these interglacial phases. This is because a lack of productive success would have led to a lack of reproductive success, and both of these relative failures would have led to a lack of success in warfare. I am not sure whether Turchin would agree with this, however, given his effective dismissal of differential productive success and differential reproductive success in explaining historical change (156-7).
But these periods of climate stability seem to have been extremely rare during the Pleistocene. Modern humans may have experienced only one interglacial period other than the current Holocene (Lewis and Maslin, 2018, 221). Not much time, then, for selection through warfare. So, for most of human history, Turchin effectively accepts that differential survival and reproductive success would have been the primary selective forces.
(IX) Hunter-Gatherers in the Early Holocene
1. With the end of the Pleistocene, around 12,000 years ago, the climate became warmer, and climatic oscillations became less extreme (171, 214). These new climatic conditions had consequences for human populations:
The new [climate] stability allowed them [human populations] to increase unchecked by their environment, which was good – for a while (214).
So the Holocene led to population growth. These growing populations migrated, colonising newly-habitable areas, filling the earth with foraging bands (171). Empty space began to run out (215) and, “as landscapes filled up, populations inevitably came into conflict over valued resources; a great fishing spot, say or a grove of nut trees” (214). This resulted in the spread of higher levels of warfare (215).
Turchin also offers a slightly different possible scenario after the post-Pleistocene landscape filled up with hunter-gatherer groups:
Now, suppose that something happens that raises the level of warfare in the region – climate change, say. When the climate became dryer and cooler during the period known as the Younger Dryas (12,800-11,500 years ago), the productivity of plant communities declined, which caused a decrease in the carrying capacity for people who depended on these resources (the availability of game animals also decreased because their food base shrank). Scarce resources led to a spike in conflict between tribes (ethno-linguistic groups) as each group attempted to expand its territory to compensate for its reduced carrying capacity. Alternatively, perhaps no special climatic trigger was needed. As the landscape grew more crowded, neighbouring groups increasingly came into conflict over resources that were growing harder to find (173).
People could already fight. For tens of thousands of years they had possessed projectile weapons such as the spear-thrower (atlatl), sling, and bow (214). These weapons had been developed during the later Pleistocene (a period of “rare” and only “sporadic conflict”) primarily for hunting, and occasionally killing upstarts (214-5).
This increasing warfare of the early Holocene was increasing external warfare, that is conflict not just between “groups”, but also between “tribes” and “populations” (173, 214). The sort of warfare, then, that leads to more rapid cultural evolution.
The Mediterranean and the Near East filled up first. (This was presumably because the productive circumstances in these regions were more favourable to population growth.) Warfare then became more common, spreading to all habitable areas (215).
The Holocene epoch, the current interglacial, is a period of climate stability initially similar to other interglacials during the Pleistocene, and presumably similar, therefore, in its initial effects upon human societies (until the development and spread of agriculture, and then industry, extended the interglacial, perhaps turning it into a super-interglacial (Lewis and Maslin, 2018, 11, 216-23)). The similarity of Turchin’s (215) description of the early Holocene to his description of earlier interglacials (169), supports this view that the Holocene was at first similar to Pleistocene interglacials.
And, just as Turchin effectively resorts to a change in productive circumstances to explain a rise in population and in the level of warfare during previous Pleistocene interglacials, so he effectively resorts to a similar change in productive circumstances to explain a rise in population and in the level of warfare in the early Holocene.
The shift from the Pleistocene to the Holocene certainly allowed human populations to increase. But this was because the productive circumstances had changed. In one scenario, the change in climate had given rise to a better-resourced (from a human perspective) environment, leading to denser populations. This is followed, in Turchin’s alternative scenario, by a decreasing “productivity of plant communities” and “availability of game animals” (173) caused by the Younger Dryas, and this led to population pressure and increased warfare. Both scenarios that Turchin suggests rely upon the effects of climate change upon productive circumstances. So it was a change in productive circumstances that explains a shift towards higher levels of reproduction (at least temporarily) and of warfare.
2. But rather than simply saying that a changing climate (or changing productive circumstances) led to population growth, which in turn led to more warfare, a selective theory of history should describe these as selective processes. Changes in climate or in productive circumstances do not change the frequencies of cultural traits without some sort of selective process.
Turchin describes the population growth before the development of agriculture as an effect of changes in climate, as the Pleistocene gave way to the Holocene (171). But he does this without invoking differential reproductive success in his explanation of that population growth. He refers to an “unchecked” (214) increase in population, but this is surely too strong, especially given his ignoring of any between-group differences in reproductive success. Did populations increase equally for all groups, or was there selection through differential survival and reproductive success?
Because of the more propitious productive circumstances of the Holocene, population levels could grow beyond what had been possible in the Pleistocene. But this population growth must have involved between-group differences in reproductive success. It is inconceivable that all groups would have been equally successful in reproducing themselves. So differential reproductive success now had the effect of raising levels of reproductive success, and therefore population levels, beyond what they had been in the Pleistocene.
This differential reproductive success must also have been due, in large part, to differential productive success: the more productive groups (more productive, that is, in the new productive circumstances) would surely have expanded more rapidly than the less productive groups.
Turchin’s view that warfare increased as a result of population growth during Pleistocene interglacials, and after the shift from the Pleistocene to the Holocene, seems plausible. But Turchin omits to say that this must have been a situation in which the change in productive circumstances had led to selection for increased warfare. Warfare does not increase over the long term unless selection favours such an increase. Warfare will become more common, not simply because of increasingly dense populations giving rise to (or in conditions of) potential scarcity, but to the extent that the fitness benefits outweigh the fitness costs for the victors (or at least to a greater degree than the benefit/cost ratio for the defeated groups). Of course, denser populations may well “raise the level” (173) of warfare, but we need to be clear about the selective processes that lead to this.
Turchin does say that the increasing level of warfare made extinction more probable if the war was lost (173). Obviously, extinction would not have been good for the fitness of the losing group (and therefore would enhance at least the relative fitness of the victorious group). But this presupposes higher levels of warfare, so the risk of extinction can hardly be part of the context that explains selection for more warfare. And extinction is, anyway, an extreme case. If there is to be selection for increased warfare, there must standardly have been differential fitness effects favouring victorious over defeated groups.
In a sense, both the Pleistocene and the early Holocene, as described by Turchin, involved resource pressure and, in both epochs, people enhanced their fitness by enhancing production. But, to put it crudely, during the Pleistocene, people competed for resources more with the inhospitable climate than with other people; during the early Holocene, on the other hand, people competed for resources more with other people than they had during the Pleistocene, and less with the (more propitious) climate than they had during the Pleistocene. (Which does not entail, of course, that, during the Holocene, they competed more with other people than with the climate.)
One difference between Pleistocene interglacials and the early Holocene, perhaps, is that the weapons developed “primarily for hunting” (214) were among the changed productive circumstances that explain why higher levels of reproduction and of warfare began to be selected for in the early Holocene. These weapons may not have been as developed during earlier interglacials.
3. Turchin repeatedly says that endemic warfare was the normal situation among pre-state societies, before the development of large states:
Insecurity and war, with a constant threat of sudden (or worse, excruciating and degrading) death, was the typical condition of human societies before ‘civilization’ – before large-scale states with their governments and bureaucrats, police forces, judges and courts, complex economies, and intricate division of labor… life in small-scale tribal societies was much more precarious and violent than most people realize… (26).
He refers to a very high rate of violent deaths seemingly due to warfare in small-scale societies (26-7), and he sums up:
The evidence is overwhelming that daily life in the shadow of imminent violence was the rule rather than the exception for people in tribal societies… … the main and most terrifying threat came from outside their society. It came from strangers (30).
Given the A-shaped curve of war over the last 10,000 years (169, 171), I assume that Turchin is not referring here to the hunter-gatherer bands of (most of) the Pleistocene, during which, he says, warfare was “sporadic” and “rare” (169, 214, 215). He is referring, presumably, to small-scale societies after the population expansion that followed the onset of (the improved productive circumstances of) the Holocene, when, as he also says, warfare became more common. But he is not explicit about this here, and he perhaps should have made this Pleistocene/Holocene distinction in levels of violence among small-scale societies much clearer in these generalisations.
4. So, returning to Turchin’s account of the early Holocene, in conditions of increasing warfare, there was selective pressure to increase the size of groups. Alliances were made:
The new conditions of intense warfare [among early Holocene foragers] raised the probability of extinction when a group lost a war. This meant that there was now a strong pressure to increase the size of the cooperating group, something most readily accomplished by allying with other, culturally similar groups (173).
Turchin effectively distinguishes between a “conquest” route to growing polity size and an “alliance” route. And he argues that military competition between small-scale, egalitarian polities favoured growth by alliances with “culturally similar groups” (173) more than growth by conquest. This is because small-scale, egalitarian polities did not take over land. Among large, state-level polities, by contrast, military competition seems to have favoured growth through conquest of other polities more:
… conquest is what centralized societies do. Small-scale, egalitarian societies fight for many reasons, but subjugation of territory or people is rarely an explicit war aim for them… it seems reasonable to assume that small-scale societies in the past also fought mainly from motives of revenge and plunder (155).
But the “explicit war aim” or the “motives” behind warfare in small-scale societies are not relevant here. The issue is whether polity growth was in fact achieved by alliances more than by conquests. Any motives involved are irrelevant to this issue.
More importantly, Turchin’s claim that small-scale societies rarely fought to achieve a “subjugation of territory or people”, that is rarely fought to conquer or control territory or people, effectively contradicts other things that he says. On foragers during Pleistocene interglacials, for example, he says that:
Nomadic foragers can be as territorial as farmers, and will defend rich hunting groups or patches of valued plant resources (169).
And, as we have just discussed, he claims that increasing territorial conflict among foraging bands in the early Holocene (whatever the proximate motives involved) was due to population growth and “scarce resources” such as “a great fishing spot… or a grove of nut trees”, so that “each group attempted to expand its territory”, and the resulting conflict could lead to the “extinction” of the losing group (173, 214).
This “subjugation” of land by human foragers is surely not surprising. Wolves expand their pack territory through between-pack violence (170), as do chimpanzees (Morris, 2014, 288-91), so why not human foragers?
Discussing early farming villages in the Holocene, Turchin says that
When people first started cultivating plants and settled in permanent villages, war between tribes became more intense. Defeat now could easily result in the loss of land for growing crops, which meant starvation (38, my emphasis).
Turning to ethnographically-known farmers, Turchin approvingly quotes anthropologist Mervyn Meggitt describing interclan warfare among the Mae Enga in the central highlands of New Guinea, in which “the execution of surprise attacks or invasions with the aim of achieving a total rout that opens the enemy’s territory to occupation” (113, my emphasis) was the first of six “distinguishing features” of interclan warfare. And these clans were “very small-scale societies indeed” according to Turchin (113; see also 118).
Of 34 examples of clan warfare among the Mae Enga of which the outcome is known, 6 led to the eviction and dispersal of the losing group. In another 19, the victorious group increased its land holdings. The remaining 9 ended in stalemate, in which neither side gained land (113). So, in 25 out of 34 wars, around three-quarters, some land was gained by the victorious group. Such small groups could be “extinguished” when they lost their land in this way (118). Given that 6 of these 34 wars led to the “eviction” of the losing clan, and their “dispersing” among other clans (113), this seems to show that, in this clearly short period of which the anthropologist had records, six clans may have gone extinct.
So war among “small-scale, egalitarian” societies led, according to Turchin’s own account, not only to the conquest of territory, but also to the subjugation, or at least the elimination or eviction, of people.
Warfare among small-scale societies is clearly serious in terms of casualties (26-7). Among the Mae Enga, warfare was the main killer of males, with around one-third of male deaths due to warfare. (112). Turchin sums up his view of Mae Enga warfare:
In short, more than a third of the men, and quite a few women were killed every generation, some clans disappeared, and victorious clans expanded territory… (118).
Among the Native Australians, ethnographically-known foragers, there seem to have been similar rates of death to the Mae Enga, that is, over one-third of men died in war (120). In small groups, losses of 10-20% of adult males can threaten the survival of the group (121).
This evidence is consistent with Turchin’s claims elsewhere that “the societies that possess them [the right institutions] destroy those that don’t” (20, my emphasis), that “military competition eliminated less cooperative societies” (42, my emphasis), that “throughout the vastness of human history, it has been the brutal forms of between-group selection that have predominated” (118, my emphasis), and also consistent with his focus upon the role of terrain in actual warfare rather than just under the threat of war (119-20). But neither these claims nor the above evidence is consistent with his dismissal of conquest, as opposed to alliances, as the source of growth among small-scale polities.
Three out of four forms of (direct) cultural group selection that Turchin (116-7) discusses elsewhere involve conquest, and one involves genocide. Conquest and genocide surely involve a “subjugation of territory [and of] people” (155). So the “subjugation of territory [and of] people” may have been more important across more of history than Turchin (155) allows.
This raises further questions. If alliances were more important than conquest for polity growth before the emergence of centralised polities (155), then selection among small-scale polities that did not conquer land or subjugate people must have been through differential success in forming alliances (presumably at least under the threat of war) rather than differential success in conquest. (Paradoxically, it seems that, for Turchin, it was the threat of warfare, rather than warfare itself, that led to polity growth in the early Holocene.) So what was the price of failure to form alliances (other than a failure to grow larger)? Not conquest by other small scale polities because, supposedly, such polities rarely conquered land. Eventually, presumably, the price paid would be conquest by those polities that had become larger and centralised. But, in Turchin’s account, that does not happen until the development of centralised chiefdoms (around 7,500 years ago in Mesopotamia), and after the development of agriculture (16, 38-9). In the millennia before that happened, there does not seem to have been any price other than remaining small.
I suspect that the growing size of polities before the development of centralised polities (chiefdoms and states) had more to do with conquest than Turchin (155, 173) allows (and also more to do with increasing reproductive success and population growth). It is, of course, an empirical matter whether alliances or conquests contributed more to the growth of small-scale societies. But Turchin is surely not only inconsistent here, but also too prescriptive in saying that conquest was rare.
5. There is another issue here. Does warfare among small-scale band and village polities have selective effects in changing the frequencies of cultural traits? “War is an evolutionary force of creation”, says Turchin, “only when it results in some cultural traits outcompeting others” (116). Turchin’s preferred “allying with other, culturally similar groups” (173) might result in the expansion of polities. But, with little variation between these “culturally similar” groups, there would presumably be little change in the frequencies of cultural traits within the larger population as polity size increased, and so little cultural evolution, no matter how strong the "selective" forces involved, as Turchin (118, 119) emphasises elsewhere. (As I touch on below (and in section XI, subsection 5), however, Turchin does need to assume the existence of at least the variation required for the evolution through selection of large-scale rituals and the associated monumental architecture, and for any changes in social structure as polities grew in size.)
The most “readily accomplished” (173) way of growing polities may (or may not) have been through forming alliances with culturally similar groups rather than by conquest. But a more effective way of changing the frequency of cultural traits is surely through the takeover of land from culturally dissimilar groups, and the “genocide”, “ethnocide/culturicide” or “assimilation” (116-7) of these groups that Turchin emphasises elsewhere. Without these, on Turchin’s own criteria, there would seem to be little or no change in the frequency of cultural traits, and little or no cultural evolution.
So perhaps what Turchin should have argued here is that those small-scale polities that allied more effectively with culturally similar groups were more effective at conquering culturally dissimilar groups and taking over their land, and it was these conquests, accompanied by the genocide, ethnocide or assimilation of the people, that significantly changed the frequencies of cultural traits, and thus brought about cultural evolution. But conquest and subjugation were not, says Turchin, what small-scale, egalitarian polities did (155).
6. Turchin concludes his account of social development before the sustained emergence of agriculture by turning to the emergence and role of monumental architecture among post-Pleistocene foraging societies, such as the “temples” built by foragers at Gobekli Tepe around 11,000 years ago. As populations grew in the new (productively favourable) conditions, (selection for and through) increasing warfare led to larger polities, built through alliances of culturally similar groups. But a new “social glue” was needed in order to make these alliances work more effectively (173-4). These “tribal” societies had no monumental architecture, indeed little architecture of any kind (14). But large-scale rituals, and the building of the monumental sites (such as henges and megaliths) associated with these rituals, increased internal cohesion, and bonded these larger groups (173-4). So larger groups that cooperated in monument-building also cooperated more effectively in other ways than those larger groups that did not build monuments (11). So, however, “culturally similar” these allying groups were (173), the between-group variation that was required for the emergence through selection of large-scale rituals and monumental architecture must, presumably, have existed.
Turchin’s (155, 173) insistence that polity growth, and presumably other processes of cultural evolution, before the emergence of centralised polities happened much more through alliances between culturally-similar groups than through conquest by culturally-varying groups seems to embroil him in a host of problems and contradictions. These claims are not essential to destructive creation, and it would perhaps be better if Turchin dropped them.
(X) The Development of Agriculture
1. Between 12,000 and 10,000 years ago, says Turchin, foragers in the Middle East began to settle in “semi-permanent villages, made possible by the abundance of wild cereals (emmer wheat, einkorn wheat, and barley) that grew in natural stands in the Fertile Crescent in the Middle East” (14, my emphasis).
So productive circumstances, this “abundance of wild cereals” (presumably brought about by climate change), made settlement in “semi-permanent villages” possible. But that a cultural trait is “possible” does not entail that there will be selection for it. The trait has to enhance fitness, in the given (productive) circumstances, more than do the available alternatives. In this case, given the increased abundance of wild cereals in this region, semi-sedentary foraging seems to have enhanced fitness more than purely nomadic foraging. Remaining as fully nomadic foragers may also have been “possible”, and was probably chosen by some, but it was selectively disadvantageous. So it is not a question of what makes a shift to semi-sedentary foraging (and then agriculture) “possible”. It is a question of the productive circumstances that make such a shift productively, and therefore reproductively and/or militarily, more advantageous than fully nomadic foraging.
Shifting to agriculture, however, had “huge health costs” (174). Stature decreased, possibly because of a decline in the quality of nutrition, and there was a higher rate of disease through increasing population density and proximity to domesticated animals (173). But agriculture did have advantages over foraging:
Most likely, people who lived in the Fertile Crescent had already known about techniques needed to intensify plant production (there is scattered evidence of episodic cultivation going back 100,000 years). Previously there had been no reason to switch to the more laborious and less healthy life of a cultivator. But another way to increase group size, in addition to building alliances, is simply to have more warriors. Growing their own food enabled human groups to raise more warriors and concentrate them within larger war bands…
The logic of cultural group selection also explains why agriculture was adopted in spite of its huge health costs. Groups of poorly nourished – perhaps even chronically sick – farmers were able to exterminate healthy and tall foragers simply by force of numbers…
Growing food instead of gathering it, requires more work and has substantial health costs, but it makes land much more productive… Tilled fields can support many more warriors than the same area under forest. The military value of agriculture is huge and trumps the costs. When farmers and foragers come into contact, farmers always win eventually and farming spreads (unless the area is unsuitable for agriculture) (174, 175, my emphasis).
It is not, surely, that there had been “no reason to switch” to cultivation “previously”, or that there must have been a “compelling reason” now. It is that a transition would not “previously”, in the productive circumstances of the Pleistocene, have enhanced productive success, and would not, therefore, have enhanced reproductive or military success.
But in the new productive conditions brought about by the shift from the Pleistocene to the Holocene, and of selection for (and so increasingly selection through) increased warfare, the greater productivity of farmers allowed them to support denser populations, and therefore more warriors. So Turchin (174) effectively says that, in transitions to agriculture, differences in levels of production between foragers and (proto) farmers were decisive for military competition. Or, as he puts it in a different context, “material wealth was becoming more important than martial prowess for war” (221).
In order to explain the spread of cultivation and farming, therefore, Turchin (174, 175) invokes the enhanced productive success of (proto) cultivators in “growing their own food” to explain their enhanced reproductive success in raising and supporting more people (and therefore more warriors), which in turn explains their enhanced military success.
This is more or less the way that Darwinian historical materialism would explain the transition (as in the Histories section of this website). I would, however, suggest two qualification. The first would be that higher levels of production can enhance military success in ways that do not always work through higher reproductive success (such as the manufacture of more and/or better weapons). The second, and perhaps more important, qualification is that farming will not be more productive than foraging in all circumstances (I discuss this further in sub-section 3 below).
But Turchin has already dismissed (group) selection through differential productive or reproductive success (156-7):
There are many methods by which a polity can improve its chances in military conflict. One is to manufacture better weapons or armor. But technological evolution in prehistory was so glacially slow that both sides in a conflict would quickly exhaust the stocks of available technology that could give them the edge against the enemy. Any new technological breakthrough was rapidly adopted by all groups, and none gained more than a temporary advantage from it… A much more promising route to victory [than technological innovation] is to bring more warriors to the conflict… A polity could breed more warriors, but that’s a slow process. Or it could form an alliance with other polities, radically and rapidly increasing the size of the allied army (156-7, my emphases).
As I have said, if “any” technological innovations would quickly diffuse to “all” groups (156), then any such innovations involved in the transition to farming would at best bestow a temporary (productive or military) advantage.
And, if these technological innovations had given rise to differential reproductive success, breeding more warriors would anyway have been too slow a process (156-7). Other polities could have “radically and rapidly” increased their size through alliances. So there would have been no selection through differential reproductive success (leading to differential military success) for a transition to agriculture. And perhaps no transition at all, if these other polities that “radically and rapidly” increased their size through alliances had been foraging polities.
So, whatever the explanation of the development and spread of agriculture, a Darwinian-style selection could not have been a significant part of the processes involved if we accept Turchin’s (156-7) general claims about the relative unimportance of differences in production and reproduction given such rapid diffusion and alliance-making. (It is worth remembering here that the transitions to virtually full dependence upon farming were very protracted, typically taking millennia.)
Perhaps the only alternative we would be left with would be a rational choice explanation of the transitions. But this would perhaps be implausible given the disadvantages of farming that Turchin (173, 174) has already emphasised.
2. When Turchin generalises about the last 10,000 years of human history, differential productive success and differential reproductive success are dismissed and replaced, when explaining the growth of polities (which he clearly sees as the primary long-term trend in that period), by differential success in forming alliances (particularly for small-scale polities) and then conquest (for centralised polities). When he has to explain transitions to agriculture, however, Turchin resorts to the effect of differential productive success upon reproductive success in allowing the breeding of more warriors.
Why say, in effect, that differential productive success is rendered selectively insignificant by “glacially slow” technological development and “rapid” diffusion (156), but then invoke it for transitions to farming (174, 175)? (And not only, as we shall see, for transitions to farming.)
And why was differential reproductive success rapid enough to effect major historical change during the transitions to agriculture (174), but not rapid enough to effect major historical change after those transitions (156-7), and therefore not significant enough to warrant a mention in the context of other historical changes? Did historical change accelerate so much after the development of agriculture?
But it is not difficult to understand Turchin’s dilemma here. He seems to see that military competition selecting geographically larger (but not demographically denser) polities through alliances simply does not explain transitions from hunting-gathering to agriculture. After describing polity growth through alliances, cemented by rituals and monuments (and just before turning to the development of farming), he says “But it wasn’t enough” (174), as if recognising the inadequacy of processes of growth through alliances for explaining transitions to agriculture.
He therefore resorts to the mechanisms of differential productive and reproductive success, arguing that shifting to farming would enhance military fitness because it would allow polities to “raise more warriors” (174), although he dismisses a “breed more warriors” (156-7) strategy when generalising about historical change. So this one resort to differential reproductive success in his account of the history of the last 10,000 years (174-5) seems to be simply an arbitrary device, useful to explain the otherwise inexplicable, and not part of his general theory.
This contrast between his fairly explicit use of differential reproductive success in explaining transitions to agriculture and his ignoring of it elsewhere, makes it clear that I am right to say that differential reproductive success plays no part in Turchin’s general theory of historical change over the last 10,000 years (156-7).
Significantly, Turchin’s (174-5) summary of the “logic of [his] explanation” for the development of agriculture makes no further mention of differential reproductive success.
3. And there is a further problem. Apart from a very brief mention of changed productive circumstances (“the abundance of wild cereals” (14)), Turchin simply assumes that (a transition to) farming would raise levels of production. But that is only true in the appropriate productive circumstances. Shifting to farming would only lead to “many more warriors” (175) in those productive circumstances in which such a shift would enhance production (and thereby enhance reproductive success). In different productive circumstances, making that shift might not have enhanced, and might even have reduced, productivity, and therefore reproductive success. Productive circumstances explain which cultural innovations will enhance production, so the changed productive circumstances (brought about by the changing climate) explain why a shift to farming was selected for (through differential reproductive and military success).
The productive circumstances do not seem to have been so conducive to a sustained shift to farming anywhere before the end of the Pleistocene. Turchin (174) says that there was “episodic cultivation” during the Pleistocene. But a sustained development and spread of cultivation did not happen during the Pleistocene, whereas it did (in certain regions, at different times) after the Pleistocene had ended. This was surely because productive circumstances had changed as the cold, dry and unstable conditions of the glacial gave way to the warm, wet and stable conditions of the interglacial (the Holocene). This shift in productive circumstances allowed human populations to expand (through differential reproductive success), but it then meant that selection no longer simply maintained efficient hunting-gathering but, in some regions and at different times, favoured a transition to farming.
If the innovations involved in that shift to farming had not, in the new productive circumstances, enhanced productivity, and thereby enhanced reproductive success, then no amount of intense warfare would have led to the development and spread of farming, because there would not have been more farmers than foragers. After all, productive circumstances during the Pleistocene (most of human history) meant that, for perhaps one hundred millennia (174), there seems to have been selection against any innovations that moved groups too far towards farming.
Even in the Holocene, innovations that might have led to farming failed to establish themselves against foraging in many regions. Where a shift to farming did occur, the timing of that shift varied widely because of variations in productive circumstances. And the populations of some regions even seem to have shifted forwards and backwards along the foraging/farming continuum, presumably as productive circumstances changed (Diamond, 1998, 54, 109). So we cannot simply assume that farming is always, irrespective of productive circumstances, more productive than foraging.
But Turchin says virtually nothing about why farming developed in some places and circumstances, but not in others. His only explicit suggestion is to point to an “abundance of wild cereals” in the Fertile Crescent (14), and he ignores other regions where transitions to farming occurred. Given his claim that farming groups “were able to exterminate… foragers simply by force of numbers” (174, my emphasis), then perhaps he would argue that agriculture developed in those regions that allowed intense, external warfare. But his claim that agriculture developed and replaced foraging because it was more productive seems to commit Turchin to the further claim that agriculture developed when and where it was more productive than foraging, rather than developing in those terrains that allowed intense, external warfare.
(XI) The Development of Chiefdoms and Archaic States
1. In Turchin’s account of the evolution of polities, highly centralised archaic states developed from centralised complex chiefdoms, which developed from simple chiefdoms, which developed from egalitarian villages. How does Turchin explain this emergence of hierarchy?
Small-scale agriculturalists were nearly as egalitarian as hunter-gatherers, with no large differences in wealth, status or power (at least within, if not between, genders and generations) (135-6). But the development of chiefdoms, and especially of despotic archaic states, reversed the trend to greater equality (136).
Turchin’s explanation of this process begins with the claim that cultivation in permanent settlements made warfare more intense because defeat now meant a loss of land, and the possible extinction of the group (38). In these conditions of increasingly intense warfare, societies came under intense selection pressure:
When people first started cultivating plants and settled in permanent villages, war between tribes became more intense. Defeat now could easily result in the loss of land for growing crops, which meant starvation… Because the consequences of losing were so grave, societies came under great evolutionary pressure to get better at surviving war. This mean inventing better weapons and armor, building up social cohesion, and adopting better battlefield tactics (38).
It is odd that Turchin (38) claims here that “getting better at surviving war… meant inventing better weapons and armor” (and presumably producing them in quantity) when, as we have seen above, he elsewhere dismisses the selective effects of the “manufacture [of] better weapons and armor” by saying that no polity “gained more than a temporary advantage” from “any new technological breakthrough” (156). Once again, a claim that Turchin makes when explaining a particular historical process effectively contradicts a claim that he makes when making theoretical generalisations about history.
This claim on the importance of “better weapons and armor” (38) surely means, moreover, that more productive societies had an advantage over less productive societies, other things being equal, as Turchin effectively accepts elsewhere (198). An emphasis on the role of differences in productive success in explaining differences in military success (and in reproductive success) is important for me because it provides the rationale for Darwinian historical materialism’s claim that (changing) productive circumstances explain (changes in) what differential military and/or reproductive success select. In this case, a shift to cultivation explains a shift to differential military success selecting for more intense warfare.
2. Turchin goes on to say, however, that there were more effective strategies than manufacturing better weapons:
But the best thing you could do was simply become a larger group, so that you could bring big battalions to the fight. This inexorable evolutionary logic forced villages to combine into larger-scale societies (38).
As we have seen, the long-term shift to larger polities that we see in Turchin’s outline of history occurred because larger polities tend to be victorious over smaller polities in warfare (or because, facing the threat of war, culturally-similar polities allied with each other). So farming villages combined into loose alliances or confederations, then into simple chiefdoms (38-9):
Gradually, single villages and less cohesive combinations were either conquered and annexed by a growing chiefdom, or simply wiped off the map. The same evolutionary logic induced chiefdoms to combine in yet larger-scale societies – complex ‘chiefdoms of chiefdoms.’ Those, in turn, scaled up into early states and empires, and eventually into modern nation-states. At every step, greater size was an advantage in the military competition against other societies (39).
This development of chiefdoms, the first centralised polities (16), presumably marks the point at which Turchin changes from emphasising alliances as the main source of polity growth (173), to giving more emphasis to conquest as a source of growth (39), because “conquest is what centralized societies do” (155, my emphasis). It is as (proto) chiefdoms developed, Turchin would presumably say, that their growth “strategies” shifted away from alliances, and towards ones in which smaller polities were “conquered and annexed… or simply wiped off the map”.
But note the sources of this growing size of polities. It seems to have taken place entirely through a (shifting) combination of alliances and conquests (38-9). Differential reproductive success, the selective mechanism that Turchin used to help explain transitions to agriculture, is now simply ignored. Nor is differential reproductive success mentioned as playing any part in selecting for the higher agricultural productivity that would be the foundation for long-term population growth. So, as far as Turchin’s theory would predict, these growing polities had populations that were larger, but no denser.
For me, polity growth also involves a growth in population density: the productive development (selected for by differential reproductive and military success) that led to larger polities, also led to population growth, and thus increasingly dense populations. But Turchin (except when explaining transitions to agriculture) ignores differential reproductive success during the Holocene, and does not connect production and reproduction. So there is no mechanism in Turchin’s general theory that would lead to higher populations. In principle, larger polities could simply be larger in area, and have higher populations only as a consequence of their larger size.
3. Military competition (given the productive circumstances of settled agriculture) gave rise, then, to a trend to growing polity size, but military competition also led to the development of hierarchies.
Of course, “superior weapons and numbers of combatants” (158) are important in warfare, Turchin says, but “training, discipline, unit cohesion, and overall coordination of military effort are also very important” (158). And chain of command is crucial. So there is selection for larger military forces (and so selection of larger polities) and selection for military hierarchy (158-9):
Command and control functions are particularly challenging for the military force of a tribal alliance. An effective chain of command, with a single overall commander, is what makes the difference between a mob and a real army… This means that under conditions of intense warfare and a real existential threat to groups that are defeated, we should expect a strong selection not only for larger size, but also for effective military hierarchies. In fact, these two processes work together, because the larger the military force, the more need there is for efficient command structures to ensure that the whole force can be brought to bear on the enemy in a coordinated fashion (158-9).
So there is selection for a military chain of command. But how do these military hierarchies lead to social hierarchies? Describing the views of the anthropologist Robert Carneiro, Turchin says that
he allows either the conquest route or the alliance route to the centralization of power, but thinks the alliance route the more likely. I agree (160).
In fact, however, Carneiro suggests that the “first permanent chiefdoms” were established
either through a chief’s peremptory refusal to relinquish his once-delegated war powers, or (less likely perhaps) through the outright conquest of neighbouring villages by the chief of the strongest one… (quoted at p. 160).
So Carneiro is actually distinguishing between a “conquest route… to the centralization of power” and what we might call a military coup route (160), and he opts for the latter as more likely. (The multi-village alliances that Carneiro mentions (quoted at p. 159) are really a route to polity growth more than to hierarchy, and seem to precede both the conquest and the military coup routes to hierarchy.) Turchin (160-1) effectively agrees with this. Not only do persistent military hierarchies become political hierarchies, Turchin says, but they also become oligarchies, and develop a tendency to corruption (159).
According to the story told by Turchin, therefore, a change in productive circumstances (the development of agriculture) led to a change in the kind of cultural traits that were selected (more intense warfare, military hierarchy, political hierarchy), and turned human history around, from egalitarian bands and villages to despotic chiefdoms and states.
I would differ in emphasising the role, in this process, of emerging political hierarchies in raising levels of production (as I will elaborate below), but this (implicit) role that Turchin gives to productive circumstances is, once again, broadly the explanatory structure suggested by Darwinian historical materialism. Indeed, this explanatory role of (changing) productive circumstances is what makes Darwinian historical materialism a (non-Marxian) version of historical materialism. Productive circumstances do not, of course, feature at all in Turchin’s theoretical claims, but their introduction here (and elsewhere) perhaps demonstrates the difficulty of explaining these historical processes without introducing them.
4. Archaic states were the first large-scale complex polities (132). They were also extremely hierarchical. Those polities that became larger and urban, with writing and a division of labour, and did develop states, developed states that were usually centralised and despotic (133, 136).
Divided into a commoner majority, slaves, and a small class of nobles, at the head of which was a divine god-king, archaic states were perhaps the most unequal polities that ever existed (132-3). There was growing inequality, not only on Earth, but also among supernatural beings, with the appearance of gods who were distinct from other supernatural beings, and who were worshipped (190). These early states practiced human sacrifice, the victims of which were provided by the slave class (133). This pattern of extreme inequality was common for almost all archaic states (135).
Early archaic states, with such economic and political inequalities, developed within a few thousand years of the emergence of agriculture in Mesopotamia, Egypt, north China, the Maya Lowlands, the Basin of Mexico, the Peruvian Andes, and southwest Nigeria (135, 144).7
Turchin acknowledges that agriculture preceded, and was a necessary condition of, the development of archaic states (135), but such evolution is not automatic:
A productive economy based on cultivating plants and animals is clearly a necessary condition for the rise of large-scale, complex societies with great disparities in wealth and power. But there is nothing automatic about this connection. It takes at least 100 human generations for agricultural societies to develop into states, and several regions around the world resisted this transition until they were colonized by modern Europeans (139).
It took between 4 and 6 millennia from the emergence of agriculture in the region for the earliest states to develop in southern Mesopotamia, southwestern Iran, south Asia, east Asia, Mesoamerica and the Andes (138, see also 16, 180), and at least 3,000 or more years from agriculture to (proto?) states on Pacific islands (138).
Part of this involved drawn-out transitions from complex chiefdoms to archaic states (190). (Turchin’s earlier figures imply around 2,000 years (16).) Both chiefdoms and archaic states persisted for several millennia. The first simple chiefdoms in the Middle East appeared around 7,500 years ago, while the first archaic states developed around 5,000 years ago. Simple chiefdoms repeatedly developed into complex chiefdoms, then collapsed back into simple chiefdoms; and complex chiefdoms repeatedly developed into archaic states, then collapsed back into complex chiefdoms (190).
A sub-theme in Turchin’s account of the development of hierarchy is that of the problems of social organisation and order arising from growing size. It is harder for strangers to cooperate in resolving conflicts and achieving goals. Force alone will not achieve this, and order in archaic states was not maintained just by coercion. Consent, gained by religious ideologies and internalised by the populace, also played a crucial part. Cultural mechanisms to achieve this must be developed, and this is not easy, so there are lots of failed states and empires in history (39-40, 152-3).
So these long transitions from agriculture to complex chiefdoms, then to the first states, were so lengthy because new methods of legitimating centralised power needed to be developed. As we have seen, Turchin sees a coup by a chief and his retinue as crucial in this development of hierarchy (160-1). But populations were alienated by the despotism of these increasingly hierarchical polities (190). In the absence of cultural legitimation, the coups repeatedly failed, and this is one reason why the transition was so drawn out (160-1).
But however much “cycling” took place between chiefdoms, complex chiefdoms and states, wherever archaic states developed it was the result of a trend away from egalitarian villages to simple chiefdoms, then to complex chiefdoms, then to archaic states. And this transition “from nonhierarchical, independent communities to centralized complex chiefdoms and the first states was invariably associated with a dramatic increase in inequality” (156).
5. Turchin’s explanation for the development of large, hierarchical states is, of course, warfare:
Not to put too fine a point on it, it was war that first created despotic, archaic states… (22).
War was the predominant evolutionary mechanism in the development of larger polities and of big states because, in war, large polities out-compete small ones, so the vast majority of human beings now live in countries with populations of at least one million (140):
The question is, what was the specific evolutionary mechanism that allowed larger societies to out-compete smaller ones, despite the downside of despotism? And the most obvious candidate, it seems to me, is war. War is the reason why big states emerged. No other explanation really makes sense (156).
Intense warfare was probably a necessary condition for the development of those pristine, or primary (155), states that developed without an existing state in the same region, and for the development of those states that emerged near other states (167-71), and therefore within the “aura” of warfare that states created around themselves (167).
Not all regions with farming developed chiefdoms and states, of course. The people of New Guinea, for instance, developed farming very early, but they went on to live in small-scale farming polities for 10 millennia. Other regions where states did not develop independently included parts of tropical Africa and South America, and the mountainous regions of Asia between the hills of Indochina and eastern Afghanistan (138-9).
Theories of the development of states need to be able to explain why they developed in some agricultural regions, but not in others. Turchin says that an “evolutionary scenario” is needed that show why the transition occurred in Mesopotamia, China, Mexico, and Hawaii, but not in New Guinea (152), and nor, presumably, in the other farming regions that did not develop states.
Turchin does not really address the question but, in attempting to explain why states developed in some farming regions and not others, he would presumably focus on differences in terrain and their effect upon military competition and, consequently, polity growth (119-20, 158).
Polity growth is crucial here because, for Turchin (39, 158-9), increasing size is a precursor of hierarchy. Farming societies could stay equal if they stayed small. If they numbered in hundreds or thousands, they could stay egalitarian. If they numbered in tens of thousands or hundreds of thousands, then hierarchies would develop (139-40). This is because, if polities are to grow this large, they must develop hierarchies, both to wage large-scale war more effectively, and to maintain social organisation and order.
And it is the effect of terrain upon warfare that explains the extent to which polities are likely to grow:
there is an intense selection pressure for cultural groups living in flat terrain to scale up… In the mountains the selection pressure for larger societies is reduced considerably (158).
In broad, treeless flatlands (spread zones) warfare was predominantly external warfare between distant, culturally different groups, and this led to significant changes in the frequencies of cultural traits in the wider population, and selection for larger polities (116, 118-19).
In thickly forested and/or mountainous regions (residual zones), however, the terrain inhibited external warfare, and warfare was predominantly internal warfare between culturally similar groups. However intense this warfare (as in New Guinea), it did not result in significant changes in the frequencies of cultural traits, and so led to little cultural evolution (118-9). (Although it did, oddly, lead to the development of farming.) Military selection between culturally different groups was not intense in these regions, so there was no selection for larger polities (119, 138-9, 158). The resulting small polities in these regions did not need military hierarchies to compete militarily (and presumably did not need social hierarchies to maintain social order and organisation). So there were no persistent military hierarchies to transform themselves into social hierarchies via a military coup.
Turchin points out that New Guinea, despite developing farming very early, did not develop states (138-9). His explanation seems to be that, because New Guinea is mountainous and heavily forested, this fostered internal warfare between identical cultures that resulted in “next to no” change in the frequencies of cultural traits, and therefore next to no cultural evolution (118-9).
It is perhaps misleading, therefore, for Turchin to say that, in the mountains of New Guinea, selection was “very strong” (119). There was certainly intense warfare, but if the clans that engaged in this intense warfare “had precisely the same culture” (118, my emphasis) or there was “very little [cultural] variation” (119), then there could be “next to no” selection of cultural variations here. There was, on the other hand, “weak competition between ethnolinguistic groups” in highland New Guinea (119). These groups seem to have been culturally distinct “tribes” made up of seven or eight clans (111-2), so consequently there must have been weak selection between these ethnolinguistic “tribes”.
(And even with the “frozen” evolution (118) of central New Guinea, there must have been selection to maintain the reasonably efficient cultivation that has supported the population for several millennia (unless we think – as I don’t – that a rational choice process would have done this).)
In spread zones with external warfare, then, polity size increased as culturally similar groups allied with each other. But why is there no selection for increased group size where there is a high level of internal warfare (as in highland New Guinea)? Polity growth can presumably occur, even with culturally identical groups, if there is intense warfare, and therefore an advantage in being larger. Recall, that Turchin (173) sees polity growth during the early Holocene as resulting mainly from the allying of “culturally similar” groups. So average polity size can increase, even if there is no change in the frequencies of cultural traits in the larger population. Indeed, some (temporary?) polity growth actually occurred in highland New Guinea:
… some clans disappeared, and victorious clans expanded territory, but overall there was next to no change in frequencies of cultural traits (118, my emphasis).
Perhaps the solution here is that polity growth requires changes in the structures of polities (such as the development of hierarchies), and this would involve changes in the frequencies of cultural traits, and require appropriate cultural variations in order to be selected, variations that might not be forthcoming. So, in the absence of any cultural differences (a very strong assumption), there would be no advantageous cultural variation that would lead to a sustained growth of those groups possessing it, so groups presumably expanded and contracted more or less randomly, and there was no long-term growth in average polity size. (Although, as I suggested above (section IX, subsection 6), there must presumably have been enough appropriate variation between these “culturally similar” allying groups in spread zones to provide the cultural raw material for the evolution (through selection by differential success in forming alliances) of large-scale rituals and monumental architecture.)
But why did some agricultural regions develop chiefdoms, but not states? Most chiefdoms, though not all, seem to have either developed into states or, more likely, been swallowed up by emerging and expanding states. But some agricultural chiefdoms did survive into the ethnographic present. If similar conditions (agricultural villages, high levels of warfare) lead to the emergence of chiefdoms and of archaic states out of chiefdoms, then we might ask why all chiefdoms did not become states.
Of course, given that these processes take millennia (138, 139), these regions of surviving chiefdoms may not have had the time to develop states before they were conquered and incorporated by “modern” states. Alternatively, there must be significant variation between mountainous and thickly forested regions (residual zones) at one extreme, and large treeless plains (spread zones) at the other. And this variation between regions might perhaps explain, for Turchin, the ways in which farming societies develop: either staying as more or less egalitarian villages, or developing into simple chiefdoms, complex chiefdoms, archaic states, macrostates or mega-empires. (Although the Inca state and empire does seem to have developed within mountainous and, in part, heavily forested regions.)
6. In his discussion of the development of states, Turchin invokes the notion of returns to scale. Why did large-scale outcompete small-scale? Turchin suggests that the returns to scale involved provide the answer:
There is something about polity size, some great competitive advantage that it confers on the group, which explains why large-scale polities have taken over the Earth. It’s the principle… economists call ‘increasing returns to scale’…
Let us now ask, what kind of return to scale should we expect for cultural groups of 100,000 people? A million? What are such groups doing more efficiently than one of 10,000 (140)?
And he later returns to this same question:
We are still unclear about that nature of returns to scale – what did large-scale societies do more efficiently, and why did they outcompete small-scale societies (152)?
His answer, as we have seen, is military competition. (It might seem obvious that larger polities have an advantage over smaller polities in military competition, other things being equal, but see Turchin’s (157-8) discussion for some complications.)
Now, I agree that military competition will tend to favour larger polities over smaller polities, because larger polities are able to support larger armies. Military competition will therefore, as I would put it, generate a persistent tendency to larger polities. But this cannot involve an endless growth trend. At some point, diminishing returns to scale will set in.
Turchin acknowledges this point when illustrating this concept of returns to scale. He uses the example of collective hunting. For a while, as more hunters become involved in hunting megafauna, they enjoy increasing returns to scale. Hunting groups that become too large, however, begin to experience diminishing returns to scale (140).
Military competition, abstracted from a real-world setting, would simply favour larger polities indefinitely. But that couldn’t happen in the real world. Something sets limits to polity size, limits beyond which returns stop increasing and begin to diminish. Presumably, therefore, polities will grow in size over the long term to roughly the point where diminishing returns set in. So what is it that explains the shift from increasing to diminishing returns to scale, and therefore explains the “optimal” size for polities? Although Turchin (140) acknowledges that there is such a turning point, he does not tell us what it is that explains where that turning point is.
No doubt differences in terrain largely explain differences in “optimal” polity size between different regions, other things being equal. But what is it that explains changes in that optimal polity size? In my view, it is changes in the prevailing productive circumstances (including those implicated in transport and communication) that explain changes in the point at which increasing returns to scale change into decreasing returns to scale in any particular region. Changes in productive circumstance therefore explain changes in the “optimal” polity size in a region.
So the development of productive techniques (due to selection through differential reproductive and military success) explains the growth of “optimal” polity size over the long term. I would argue, therefore, that the trend to larger “ultrasocieties” actually occurred, when and where it did occur, because of productive development, including improvements in transport and communication.
Without productive development of this sort, then, the “optimal” polity size, even in “broad treeless flatlands”, would have been relatively small, and warfare, no matter how intense, would simply have maintained relatively small polities.
Turchin’s (140-2, 156) scepticism concerning the economic benefits of larger size in the pre-industrial world therefore misses the point. The benefits of larger size might be entirely military, but changing productive circumstances (including those relevant to transport and communication) could still explain changes in the inflection point at which larger size stops being militarily beneficial and starts to be militarily costly (perhaps because of logistical issues). Changing productive circumstances could thus explain changes in the point at which increasing returns to scale shift to diminishing returns to scale, and thus explain changes in the “optimal” size of polities in the given circumstances, even if there are no specifically economic benefits to larger size.
Interestingly, in the example that Turchin gives (140), the point at which increasing returns shift to diminishing returns does depend upon the productive circumstances. And his remark that “it is logistics that determine whether one society will prevail over another in the long run” (198) also implies that (militarily-relevant) productive circumstances explain where that inflection point is.
If Turchin does not think that changes in “economic production” (140) explain changes in the point at which increasing returns to scale change to diminishing returns, then what does he think explains those changes?
7. It is a plausible claim that larger polities require hierarchies both to wage war and for internal organisation and order. But I think that more is involved, and the key, again, is the prevailing productive circumstances.
Where productive circumstances allowed little (or no) productive development, differential reproductive and/or military success led to the persistence of foraging societies or agricultural villages with relatively small populations, and without hierarchies (other than, perhaps, hierarchies based upon age and gender).
Polities with a greater division of productive and social roles (and therefore more trade) spread to the extent that the prevailing productive circumstances in a region allowed levels of production to be increased by a greater division of such roles. There would have been long-term trends to a growing division of these roles in these regions to the extent that such more complex polities enhanced their productive success, and therefore their reproductive and/or military success, more than (and often at the expense of) less complex polities (with less trade). (Larger and denser populations would obviously allow a greater division of such productive and social roles.)
In productive circumstances in which social hierarchies could intensify production, but only to a limited extent and/or relatively slowly, differential reproductive and/or military success led to the development and spread of more hierarchical polities, such as chiefdoms, with larger populations (chiefdoms even developed among some hunter-gatherers). But in those (invariably agricultural) regions where even steeper hierarchies could intensify production to a much higher level, differential reproductive and/or military success led to the development and spread of state-level polities, with very large populations. (There would, of course, be selection against any polities that tried to intensify production beyond the limits set by the prevailing productive circumstances.)
(My “story” of the rise of hierarchies would focus less upon military coups and more upon the gradual emergence of “big men” and increasingly asymmetric redistributive exchange, as a way of raising levels of production. But I am not committed to this, or to any particular account of how hierarchy develops within polities. I am committed to saying that higher levels of hierarchy were selected, through differential reproductive and/or military success, because higher levels of hierarchy enhanced production within the prevailing productive circumstances. Which does not entail, of course, that hierarchies will enhance productive success in all productive circumstances.)
So, for me, hierarchies are largely explained by the continuing effect of hierarchies upon production in the relevant productive circumstances. For Turchin, though, hierarchies are largely explained by the military role of elites (140-2, 156), who acquire their social emplacement through that military role, and who play no essential economic role:
Archaic-style states of which we have direct knowledge, such as Hawaii, did not have complex economies or specialized decision-making procedures… The chiefs were involved with war and ritual; the economy worked well enough when left to the commoners (142).
Now, it is perhaps implausible for Turchin to say, of these relatively large polities, that “the economy worked well enough when left to the commoners”, when he says elsewhere that
… increased size brings with it a whole host of coordination and cooperation dilemmas… force, or threat of force, is an important ingredient in sustaining cooperation… The larger the society… the harder it is for people to cooperate in resolving conflicts and achieving collective goals (39).
But the role of elites in the Hawaiian economy was not, anyway, just a matter of ensuring coordination and cooperation. In their discussion of the Hawaiian Islanders, Johnson and Earle (2000, 284-94) describe hierarchies made up of a paramount chief, district chiefs and community chiefs. The latter appointed land managers, whose job it was to organise the construction of irrigation canals, terraces and fish ponds and, crucially, to make sure that the goods (food, craft goods, raw materials) and labour needed by the chiefs were channelled upwards in an asymmetric redistribution system (Johnson and Earle, 2000, 289-91):
Subsistence producers… generated the wealth used by the chief to compensate nonproducing personnel, to invest in capital improvements, to make political payments that extended and consolidated his control, and to finance conquest warfare designed to enlarge his income (Johnson and Earle, 2000, 292).
The economy in Hawaii may have functioned well if “left to the commoners”, but almost certainly at a lower level of production. Waging war requires resources, so military competition imposed selection for higher levels of production, and this would have meant selection for higher rates of work for the commoner majority in order to provide those resources and to provide the labour required by the elite. I think it unlikely that commoners would have imposed such high work rates upon themselves without the pressure of social elites. So, in regions that were potentially very productive, there was selection (through differential reproductive and/or military success) for hierarchies that would impose the work rates that would raise levels of production.
8. The development of the first states does seem to have occurred in such potentially productive regions. Most early states appeared in areas of high sunlight and long growing seasons, with good sources of water. These “pristine” states emerged in fertile river valleys or water basins: the Tigris and Euphrates, the Nile, the Indus and the Ghaggar-Hakra (Sarasvati), the Yangtzi and Huang-He, the rivers and lakes of the Mexico Basin, and the rivers running from the Andes to the Pacific (Scarre, 2005b, 194-5). These productive circumstances allowed high crop yields given high labour inputs. (Perhaps it is also worth mentioning, in this context, the complex chiefdoms, perhaps proto-states, that developed in the Mississippian cultures of the Mississippi and Ohio river systems (Milner, 2005, 690-91).)
Significantly, these fertile zones within which states first developed seem to have been surrounded by arid zones, or even deserts, with much less productive potential. So any farmers who fled the tribute and labour requirements of emerging elites would not only have given up all the fixed capital produced by previous generations of farmers, but would anyway have achieved significantly lower levels of production (Harris, 1978, 78-79), and therefore of reproductive and/or military success.
Among peoples whose productive circumstances entailed that increasing hierarchies and labour intensification would not sustainably enhance levels of production, even the most intense warfare would not result in sustained transitions to large, complex, state-level polities (unless, of course, they were conquered and incorporated by large, complex, state-level polities). So explaining the fact that chiefdoms and states did not develop in New Guinea, for example, involves examining the limitations of the distinctive productive circumstances there (Diamond, 1998, 146-50, 303-8).
The question of whether variation in productive circumstances largely explain why chiefdoms and states developed in some regions but not in others (my view), or whether this is largely explained by the effect of variations in terrain upon warfare (Turchin’s view), can only be resolved, of course, by a clear specification of the different claims and careful examination of the relevant evidence.
9. As well as dismissing any economic role for elites in explaining the origins of states, Turchin also dismisses arguments that focus on the economic benefits (in production or trade) of larger size (140-2, 156).
Economic benefits are relevant to modern polities, says Turchin, but they are not enough to explain the growth of polities in prehistory:
I don’t deny that large-scale social integration can also bring economic and information benefits, but the returns to scale in these aspects of social function are primarily relevant for modern societies in which war is less pervasive. Economic and informational challenges simply did not loom as large in prehistory as the existential challenge of battle (156).
(Given that war was also, presumably, “less pervasive” during the long glacials of the Pleistocene (215), when it was the “harsh environment” (169, 214-5) that imposed the “existential challenge” (a challenge that was met by production), we must again assume that Turchin is using the term “prehistory” here in a sense that, in fact, excludes most of human prehistory.)
I suspect that, for most people in prehistory, production was at least as much an “existential challenge” as battle. But the crucial point is that production is an “existential” requirement (not merely a “challenge”) for military success, and this is true throughout human history (and prehistory). And achieving higher levels of production than other polities will, over the long term, lead to higher levels of military success. Elsewhere, Turchin effectively accepts this for large stretches of history (174, 175, 221, 222), and indeed for history generally (198).
But Turchin is here counterposing “the existential challenge of battle” and “economic and informational challenges” (156) as explanatory elements that appear to be zero-sum alternatives: the more important one is, the less important the other will be. As I will show below, this is not the only place where Turchin conceptualises warfare and production in this way, a conceptualisation which I think is profoundly mistaken. It is better, as I have argued in section IV above, to see warfare and production as different, and complementary, elements in the same explanatory structure.
Another reason that Turchin (156) gives for focusing upon warfare rather than upon aspects of production in explaining the development of archaic states, is because their kings were preoccupied with war:
We don’t find boastful inscriptions from Ashurnasirpal [a ninth century BCE king of Nimrud] about trading networks or well-maintained irrigation systems. In their own official statements, the first kings were all about war. Shouldn’t we pay attention to what they tell us?
We can certainly pay attention to the first kings. But why do we have to explain long-term historical processes in terms that the rulers of archaic states would understand and accept?
(XII) The “Axial Age” and the Development of Mega-Empires
1. If it was war that created “despotic, archaic states”, Turchin says, it was also war that “destroyed them, replacing them with better, more equal societies” (22).
About 2,500 years ago, around the middle of the first millennium BCE, larger, more durable mega-empires emerged, with a new form of political power, legitimized by new ideologies (generally involving moralizing religions), and with lower levels of both internal violence and inequality. To explain this “Axial Age” of mega-empires and moralizing religions, Turchin says, we need to turn our attention to the plains of Eurasia, north of the ancient civilisations, where the Great Eurasian Steppe of grassland stretches from the Ukraine to Manchuria (190, 193).
The Eurasian steppe was where the horse was domesticated, and it was also the source of two military revolutions in the ancient world. The first was chariot warfare, while the second, more influential revolution was cavalry warfare. This second military revolution, from around 1000 BCE, originating deep in the Eurasian steppe, triggered massive changes in a belt of societies from the eastern Mediterranean to China (212).
The chariot seems to have been developed first by Eurasian pastoralists in what is now Kazakhstan around 2,000 BCE (194). Chariots revolutionised warfare, and chariot technology was quickly adopted by the agrarian states of the Near East, northern China, India, and Europe (194). In their most effective use, these chariots were a mobile platform for archers, combining ranged weapons and mobility (194, 195).
Chariots were the decisive battlefield weapon in the ancient states of Eurasia for around 1000 years, between c. 2,000 and c. 1,000 BCE, before their place was taken by cavalry (193, 194, 195). By the end of the Bronze Age, Near-Eastern empires had thousands of chariots. The Battle of Kadesh in 1275 BCE, between Egyptian and Hittite armies, was perhaps the largest chariot battle ever fought, involving five or six thousand chariots (194).
Turchin says that the nomadic peoples of the Eurasian steppes were prepared for the innovation of horse riding:
As far as the technology of horse-riding is concerned, it was the nomadic peoples of the Eurasian steppes during the second millennium BCE who were ready for it (193).
But, before they were ready for horse riding, these people of the Eurasian steppes seem to have been “ready”, preadapted perhaps, for the harnessing of horses for traction.
These Eurasian steppe peoples were pastoralists before they were mounted pastoralists, and horses were already domesticated by 3,500 BCE. Living on extensive grasslands, the nomadic mode of subsistence involved herding, milking, slaughtering and eating horses and cattle (193-4). Horses were harnessed for military purposes only around 2,000 BCE (194).
Now, there are likely to have been a huge number of innovations in this long development of horse-drawn chariots and archery, most of which will have failed in competition with superior variants, and which are therefore largely unknown to us, given that selections “covers its tracks” (Sober, 1993, 69) by destroying the variation on which it acts. Those innovations that succeeded made up what we could call the Eurasian Chariot Complex (after the Asian War Complex (28, 156)). But the crucial point, for Darwinian historical materialism, is that the development of this Eurasian Chariot Complex took place within, and depended upon, a developing productive context in which the domestication of horses, and then their harnessing for traction, enhanced productive success, and thereafter enhanced reproductive and military success.
2. During the second millennium BCE, the western steppe was dominated by Iranian speakers. Around 1000 BCE, roughly one thousand years after the development of chariot warfare, these peoples developed a new military technology, horse-riding, “a much more efficient way of using horsepower in war”, and one that dominated warfare in Eurasia for around 2,500 years (193, 194, 195).
For more than two millennia, from c. 1000 BCE to c. 1500 CE, the warhorse remained the most important military technology in the states and empires of Eurasia, and steppe horsemen the most effective practitioners of this form of warfare, until gunpowder weapons made mounted archery obsolete (195, 197). Of course, the emergence of cavalry was a protracted process of development:
Effective horse riding, good enough to use the horse in war, required very substantial technological evolution. Both the bridle and the saddle are complex contraptions, consisting of many components. Perfecting them took literally thousands of years, with constant improvements added in a cumulative fashion. The stirrup alone emerged more than 1,000 years after the first cavalry (195).
This “very substantial technological evolution” (195) necessary for the development of the new military package that we could perhaps call the Eurasian Warhorse Complex, like that which had led to the Eurasian Chariot Complex, took place entirely within a developing productive context. The techniques and technologies of controlling the horse (bridles, saddles and stirrups) were more examples of military “breakthroughs” emerging out of productive development. These innovations were not only possible, but also production-enhancing (and therefore spread), only because of the productive contexts in which they occurred. This, along with the productive circumstances out of which composite bows and iron smelting developed, favoured the emergence, through selection, of the Eurasian Warhorse Complex.
Domesticated horses, chariots and their harnesses, rideable horses, their harnesses and saddles, iron weapons and armour, and compound bows and arrows could be developed and produced (or bred, in the case of horses) in significant quantities, and become the decisive battlefield weapons, for 4,500 years (194, 195, 197) only because of the prevailing productive circumstances. It was these productive circumstances that made such innovations productively successful, that therefore allowed their sustained production and use in warfare, and that explain why military competition selected for chariot and then cavalry warfare.
Military breakthroughs that advantage offensive warfare generally seem to involve prior changes in productive circumstances, and these innovations (such as chariots, compound bows, warhorses and gunpowder weapons) all took place within the context of the development of productive technologies.
And it is changing productive circumstances (the domestication of the horse, the development of the horses and the technologies involved in horse-based transport and traction, and the development of the horses and technologies involved in horse-riding for herding) that change what selection selects, and thus changing productive circumstances that led to selection for larger, mega-empires.
(Of course, if these innovations in military technology had quickly diffused, and between-group variation in them had been rapidly eliminated, as Turchin (156) elsewhere proposes, then they would surely have had next to no selective effect.)
3. Cavalry revolutionised warfare in Eurasia, then, but it was not just warfare that was revolutionised:
The invasions of horse archers from the steppe into southwest Asia triggered a cascade of interrelated military, political, and religious upheavals. The centuries around 500 BCE saw a military revolution and intensification of warfare, which made agrarian states much more vulnerable to extinction. At the same time we see the spread of qualitatively new Axial religions and the rise of unprecedentedly large Axial empires (200).8
Steppe horse archers, the masters of this mobile warfare, could overrun agrarian states, defeat their armies, and take their unwalled towns (198-9). The solution to this new vulnerability was to increase the size of polities. A larger population meant more soldiers and more resources:
There was only one way out of this quandary: drastically to increase the size of the state. More population translates into greater numbers of recruits for the army and a larger taxpaying base to support the soldiers. With more soldiers, the state can both garrison the forts and field an army large enough to chase the raiders away (201).
So the development of horse archers was a military revolution, which intensified warfare, and which led to agrarian states being more vulnerable, a vulnerability that they overcame by growing larger, and becoming mega-empires. These multi-ethnic mega-empires required new Axial religions to legitimise them and pacify their populations, reducing inequality and internal violence. (All of these long-term developments were presumably brought about by selection, with the intentional actions of historical agents providing the variations upon which selection worked.)
As we have seen, Turchin’s account of the growth in size of non-centralised polities stresses alliances (rather than conquest) as the route to growth, whereas the growth of centralised polities takes place more through conquest (155, 173). And his account of the development of mega-empires does seem to emphasise conquest, more than alliances, as the route leading to larger size (155, 187, 202). (The historical record of these mega-empires surely supports the view that they grew by conquest more than alliances.)
He does not mention differential productive success or differential reproductive success (as he did in explaining the transitions to agriculture), so presumably he does not see them as important in the development of mega-empires. The process that gives rise to these mega-empires seems, therefore, to generate no tendencies/trends to productive development or population growth.
But increasing the size, and therefore the population, of a state (either through alliances or through conquest) might not have solved the vulnerability problem unless population density was also increased. If an alliance or conquest simply doubled the number of soldiers, but doubled the area that they had to defend, then little has been achieved. Even if expansion doubled the area (and therefore the population, other things being equal), but the length of the border was much less than doubled, this may not have helped a great deal given the mobility of the horse archers and the “strategic dilemma” (201) these agrarian states therefore faced. There would, surely, have been selection for higher population densities, and therefore for higher levels of production.
Of course, all that this threat from steppe horse archers did was to accelerate a process of polity growth that was occurring before the emergence of horse archers, and that continued after the horse archers were decisively defeated. And even while horse archers continued to be a threat, the selection for polity growth presumably continued only until diminishing returns to scale set in, after which point there would have been selection against polity growth. Unfortunately, Turchin gives us no clue as to what, in general, explains historical changes in where that point is.
4. As mentioned above (section VII), this was a period in which the proportion of people killed in inter-polity warfare fell. Turchin’s explanation is that the wars of states and empires became frontier wars, not wars near the centre of the empire, so more people lived peacefully (40-1). He also says that (increasing?) numbers of people were involved in producing and delivering the materials of war, and that production became increasingly important from around 2,500 years ago:
We saw that, although war remained the most important contest between societies, violence itself actually declined during and after the Axial Age, simply because in mega-empires a smaller proportion of the population was on the front lines. This did not mean the rest of the population was irrelevant to the war effort. It had to mass-manufacture the military equipment and supplies and deliver them efficiently where needed. In other words, material wealth was becoming more important than martial prowess for war (221).
So, although he does not explicitly mention inter-polity differences in productive success here, it is hard to see how Turchin could avoid concluding that differential productive (or logistical) success was becoming more important in explaining differential military success in this period.
But why did that begin to be true only from 2,500 years ago (and during the transitions to agriculture)? Surely, other things being equal, more productive polities (with greater “material wealth”) will generally tend to beat less productive polities (with less “material wealth”).
Of course, Turchin is right that larger polities (with correspondingly larger populations) will tend to beat smaller polities (with correspondingly smaller populations). But the more productive polities will also tend to have larger populations, other things being equal. And more productive polities will also be able to divert a larger proportion of their population from directly productive activities into warfare for longer periods, and to endure the material attrition that warfare involves. And this, too, would seem to be true across history, and not just for the last 2,500 years (and during the transitions to agriculture).
But again Turchin does not incorporate any of this into his general theory. He does not withdraw his (156) earlier general dismissal of the selective effects of differences in productive development.
(XIII) The Modern World
1. Turchin spends little time discussing the modern world. He promises another book on that topic, in which he will “trace how these transformative technologies [gunpowder, navigation and the printing press] changed the nature of competition between societies…” (213). If part of this will involve showing how these (and other) changing productive techniques changed what selection through (military and economic?) competition actually selected, then I look forward to it.
Turchin says that an important part of this inter-polity competition was the “Age of Discovery”, which saw Europeans expanding into the Americas, Asia and Africa, resulting in warfare between “civilized soldiers” and “tribal warriors” (121). In this expansion, “civilized soldiers” were more likely to defeat non-state peoples when they adopted the latter’s tactics, including
smaller, more mobile units; abandonment of artillery and use of lighter smaller arms; open formations and skirmishing tactics; increased reliance on ambushes, raids, and surprise attacks on settlements; destruction of the enemy’s economic infrastructure (habitations, foodstores, livestock, and means of transport); a strategy of attrition against the enemy manpower; relentless pursuit to take advantage of civilization’s superior logistics, and extensive use of natives as scouts and auxiliaries (Keeley, quoted in Turchin, 2016, 121).
And Turchin goes on to say that “civilized states” are generally more successful against “tribal warriors”, even while using the tactics of these “tribal warriors”, because the large, possessing more resources, almost always prevail against the small.
But notice that this seems to have nothing to do with differences in levels of productive development. Turchin says that “civilized states almost always prevail against tribal warriors in the end… because they are large-scale societies fighting small-scale societies” (122, my emphasis). Not because “civilized” states have (sometimes much) higher levels of production per capita than “tribal” polities, but because they are larger. He does go on to say that “Large states have much greater resources than tribal societies…” (122). But this resource differential seems here to be simply a function of polity size, and not also a massive difference in resources per capita.
Obviously, I would not deny the importance of size in military competition. But nor should we ignore that another crucial distinction between “civilized” and “tribal” polities is the massive differences in productive development. And when there are marked differences in levels of per capita production, the more productive will usually prevail, other things being equal. It is not just that “they are large-scale societies fighting small-scale societies” (122), it is that they are more productive societies fighting less productive societies (indeed, to a great extent, they are larger because they are more productive). This applies to much of human history, certainly since the various transitions to farming and the emergence of significant inequalities in levels of production between foragers and farmers.
One hundred pages later (221-22), as we have seen (section XII), Turchin asserts the increasing importance of “material wealth… for war” since the Axial Age. But even then he is not explicit that it is differences in material wealth per capita, or differences in productive success, that explain differences in military success. And he does not incorporate that insight into his theory of destructive creation.
2. So Turchin (221) does accept a growing importance of “manufacture” and “material wealth” from the time of the Axial Age. And after 1500 CE, and certainly by the 20th century, wealth-based competition became more important than military competition:
Wealth-based forms of competition became even more important after the next great military revolution of 1500 CE. By the 20th century, prowess on the battlefield was definitely taking a back seat to industrial organization and productive capacity… After the end of World War II, competition between societies shifted even more from the military to the economic and ideological spheres (222).
When Turchin refers to “wealth-based competition” here, he means inter-polity competition. In my view, of course, differential productive success has always been crucial to competition (military or reproductive) between groups; as Turchin puts it, “it is logistics that determine whether one society will prevail over another in the long run” (198).
Because of his failure to clearly ask and answer the fundamental question of what explains what selection actually selects, however, Turchin does not see how a selective mechanism and productive circumstances can be complementary parts of the same explanatory structure, so he seems to think of them as alternative selective forces (as I have argued above, incidentally, productive competition is not a directly selective force).
And his lack of clarity on this issue means that Turchin (222) therefore counterposes “wealth-based forms of competition” and “industrial organization and productive capacity” to “prowess on the battlefield”; economic “competition between societies” to military “competition between societies”; and economic forces as the “dominant [selective] forces” to war as the “dominant selection force”. And he sees the balance shifting from the latter to the former of each of those pairs from as far back as the Axial Age (221), even more during the modern age, and especially from the end of the Second World War (222). Turchin, here and elsewhere (140-42, 156), obviously sees warfare and production as explanatory rivals in explaining macrohistorical processes and patterns, so that as one increases in importance, the other decreases, rather than as complementary elements of a properly formulated explanatory structure.
Warfare and production occupy such complementary places in the explanatory structure that I am suggesting. Differential reproductive and military success, working at times independently and at times reciprocally, are the selective mechanisms directly responsible for increasing or decreasing the frequency of cultural traits. Differences in levels of production, for their part, largely explain differences in reproductive and military success. Although there are some notable exceptions (such as the “nomad anomaly” that Ian Morris (2010, 624; 2013, 205f) discusses), I would claim that this has generally been the case in human history.
It is because of this crucial role of differential productive success that productive circumstances explain why differential reproductive and military success select what they select. Productive circumstances explain the extent to which alternative cultural traits will (directly or indirectly) enhance production, and those that enhance production will generally enhance reproductive and military success, and thus increase in frequency. General tendencies to larger size and more cooperation (or higher levels of production, reproductive success, and military power) are, therefore, dependent for their realisation upon productive circumstances that are conducive to productive development.
3. One other issue assumes particular importance with the accelerated development in the modern world of national (and international) markets. Turchin says that
competition within groups destroys cooperation, but competition between groups creates cooperation (73).
Within-group competition undermines cooperation (93), so
to succeed, cooperative groups must suppress internal competition. Equality of group members is, therefore, a very important factor in promoting group cohesion and cooperation, which translates into the capacity of the group to win against other groups (93).
But does Turchin think that this is true of competitive markets in productively more developed economies? Does he think that this internal competition must be suppressed? In the right productive circumstances (and perhaps properly regulated), such (no doubt imperfectly) competitive markets surely enhance the productive power of a polity? Turchin effectively recognises this elsewhere, saying that “economic competition eliminates the less efficient businesses” (42). This effect of competitive markets on productive efficiency surely helps to explain why more-capitalist polities have generally prevailed over less-capitalist polities. So internal competition does not always seem to reduce the ability of the polity to succeed against other polities.
(XIV) Conclusion
1. This has been a very lengthy review of Ultrasociality , and I apologise for that (although it was a very lengthy pandemic isolation). It has also been a very critical review, though I cannot apologise for that.
I share Turchin’s desire to develop a general theory to explain long-term and large-scale historical processes and patterns. I also share his sense that the conceptual apparatus of Darwinian theory will provide an unavoidable source for that theory. But it is crucial to express these ideas clearly if they are to be tested against evidence. Clarity is also important in order to allow critics to identify problems and formulate their objections (and clearly expressing ideas might even prevent critics from misunderstanding them).
Another reason why it is important to express these ideas as clearly as possible is that doing so will perhaps enable us to reconcile the (often hostile) camps of those who emphasise the explanatory role of production in human history, and those who emphasise the explanatory role of selection through a competitive mechanism.
Turchin does not, in my view, formulate his ideas as clearly as they should be formulated. Consequently, destructive creation can be presented in different ways. But, however charitably it is presented, Turchin makes significant claims that are effectively inconsistent with each other, and this is the case whichever way the theory is presented. It is no defence against this charge, therefore, to complain that I have presented destructive creation incorrectly. Present the theory in one way, and these claims of Turchin’s are inconsistent with the theory; present it in another way, and those claims are inconsistent with the theory.
I could say, for example, that Turchin accepts as general theoretical claims (and not just for the Pleistocene (214) and the development of agriculture (174, 175)) that differential reproductive success has been an important selective mechanism in human history, that differential productive success (largely) explains differential reproductive success, and that together they explain differential military success. That would be, in my view, a sensible approach, and it would align destructive creation more closely with Darwinian historical materialism. But it would contradict what Turchin says elsewhere (156-7) in dismissing both differential productive success and differential reproductive success as relatively insignificant over the last 10,000 years, and it would be inconsistent with his ignoring of differential reproductive success in most of the rest of the book. So it does not matter what Turchin’s position “really” is, inconsistencies are inconsistencies.
I suspect that one reason that Turchin makes so many effectively inconsistent claims is that this is not a particularly well organised book. So, for example, Turchin discusses hunter-gatherers in the later Pleistocene at 108-9, 169-70 and 214-5; hunter-gatherers in the Holocene at 171-4 and 214-6; the development of chiefdoms at 38-40, of chiefdoms and archaic states at 175-80, of archaic states at 131-47 and 149-71; and the Axial Age and the development of mega-empires at 20-1, 126-8, 183-209 and 222-3. (For readers, this confusing approach is not helped by the lack of an index.) It is perhaps easy to make inconsistent claims in such widely separated discussions of the same topic.
2. To return to the two questions that I outlined at the beginning of this piece, and that any theory of history that relies upon some kind of selective process must answer. What are the most important selective forces in human history? And what is it that explains why these rather than those variations are selected?
For Turchin (214), differential survival and reproductive success (independently of military success) were the predominant selective mechanisms during (most of) the Pleistocene (which is most of human history, though many more people have lived during the Holocene).
Turchin claims that differential military success has played the main selective role (at least in explaining long-term trends) for around the last 10,000 years (except perhaps for recent centuries), while differential reproductive success seems to have played little or no part in changing the frequencies of cultural traits during this period (except during transitions to agriculture), either independently or through helping to explain differential military success.
Of course, Turchin does not explicitly say that differential reproductive success has been insignificant for most of the last 10,000 years of human history. But his general dismissal of differential reproductive success as a selective force (156-7), together with his failure to invoke it in his historical explanations (apart from the transition to agriculture (174, 175)), and his lack of discussion of population growth (as opposed to growth in the size of polities), reflect the little importance he attaches to it.
The situation is somewhat different with Turchin’s treatment of production. Turchin effectively acknowledges the importance of (differences in) productive success in his explanation of the development of farming (174, 175), and in saying that material wealth was becoming more important for war than martial prowess from the Axial Age (221) and even more for the modern world (222). But Turchin does not integrate these scattered insights into his general theory of destructive creation. If production was so important during these historical moments, then why was it not similarly important over the rest of human history (as he effectively, though not explicitly, recognises elsewhere (198))?
Turchin’s various concessions/acknowledgements here effectively combine, however, to support the Darwinian historical materialist view that, over the long term, differences in military success are largely explained by differences in productive success (and sometimes, at least partly, by differences in reproductive success that are themselves explained by differences in productive success).
And once we accept that differential productive success largely explains differential military success, and therefore that it is productive circumstances that largely explain which innovations will tend to enhance production, and therefore spread through military competition (or not enhance production, and not spread), then it follows that productive circumstances explain which cultural traits will increase in frequency and which will not.
Though Turchin dismisses “technological breakthroughs” as selectively unimportant (156), his specific explanatory hypotheses frequently rely on (developments in) productive technologies, and therefore (changes in) productive circumstances, to explain (changes in) what military competition selects (14, 72, 96-101, 108, 173, 180, 193-5, 211, 214, 215). Turchin repeatedly shows that shifts in productive circumstances (the development of projectile hunting weapons, the transition from the cold, dry Pleistocene to the warm, wet Holocene, the development of agriculture, the domestication of horses, the development of the technologies for harnessing and riding horses, the development of iron smelting and compound bows, and so on) shifted what reproductive and/or military competition selected. On the other hand, however, he does not explicitly invoke differential productive success, and there is little discussion of long-term productive development.
Destructive creation, of course, does not explicitly address this issue of what explains what selection actually selects. Turchin does, perhaps, provide some implicit partial answers, at least for the last 10,000 years, in emphasising the effects upon warfare of different kinds of terrain and of breakthroughs in military technology. But the main, if not only, effects of these have been upon the intensity of the military selection that has (or has not) created larger and more cooperative polities.
Briefly, my perspective (1993; 2002a; 2006; 2009; and the pieces on this website) says that differential reproductive and/or military success (operating both independently and reciprocally) increase the frequency of those behaviourally-transmitted (cultural) traits that, given the prevailing productive circumstances, enhance production, and thereby enhance reproductive and/or military success. Consequently, there are persistent tendencies to increasing levels of production, reproductive success and military power.
Of course, I accept that the relative significance of reproductive success and military success may have varied as circumstances changed. So a lesser role for differential military success and a greater role for differential reproductive success during the Pleistocene, as Turchin suggests, is a plausible view. (I suspect, however, that differential reproductive success has continued to play a significant part during the Holocene, though partly through its effects upon differential military success.)
And Darwinian historical materialism says that the organism-environment relationship, particularly the prevailing productive circumstances of the relevant population, explains which cultural variations the selective forces of differential reproductive and military success actually tend to preserve and spread (and the intensity of that selection).
3. There are several issues, in my view, that Turchin needs to address. First, he needs to acknowledge the contribution that differential reproductive success makes as a selective force, both in its own right and as a contributor to differential military success, not just during the Pleistocene (214) and the development of agriculture (174, 175), but throughout human history.
Second, he needs to explicitly acknowledge that differential productive success is a crucial part of any explanation of differential reproductive success and differential military success. And this, not just during the development of agriculture (174), in the development of the post-Axial mega-empires (221), and over the last 500 years of the development of the modern world (222), but again throughout human history, as he effectively accepts elsewhere (198).
Third, Turchin needs to focus explicit attention on what it is that explains, not just the intensity of selection, but what selection actually selects. To do this, he needs to focus on the people-environment relationship.
Fourth, in addressing that issue, Turchin needs to realise that, to the extent that differential productive success explains differential reproductive and military success, it is productive circumstances, more than any other aspect of the people-environment relationship, that explain whether innovations will (directly or indirectly) enhance productive success, and thereby enhance reproductive and military success. So it is productive circumstances that explain which cultural traits are likely to spread through a population. Turchin would then have an explanatory structure that integrated productive circumstances as a complementary factor to military competition, instead of seeing economic competition and warfare as alternative selective forces.
If he addresses these issues, it may be that Turchin’s position will move somewhat towards the Darwinian historical materialism that I favour.
If, on the other hand, I have fundamentally misinterpreted Turchin in this review, and if he does already think that differential productive success largely explains differential reproductive success, that together they largely explain differential military success, and that therefore productive circumstances explain which innovations will enhance productive success (and which will not), then what would he see as the differences between his destructive creation and my Darwinian historical materialism?
Notes
1. I will not discuss cultural multilevel selection in this review. In essence, it focuses upon the way that the selection of cultural traits at the individual level and the group level are both significant, but can work in very different directions (81-94).
2. For simplicity, I assume the absence of countervailing forces, such as random genetic drift (Sober, 1984, 23, 28; 1993, 18-9). This formulation also subsumes differential survival under differential reproductive success (Sober, 1993, 57-9, 209). It includes, therefore, both differential reproductive success that is explained by differential survival, and differential reproductive success that is independent of differential survival.
3. Higher reproductive success can, of course, contribute to greater military success – and vice versa – but they are not necessarily connected, and can occur independently of each other.
4. Not all forms of selection enhance fitness or adaptiveness. Frequency-dependent selection, for example, will not raise the level of fitness in a population (Sober, 1993, 95). Given the long-term, albeit discontinuous, rise in reproductive fitness (and military power) for the human species taken as a whole, however, I will ignore that issue here.
5. These cultural traits would include varying productive techniques, and those social relations and cultural norms and values that, directly or indirectly, affect production.
6. For more discussion of the issue of diffusion, and the threat it poses to a selective account of history, see Nolan 2002b (80-1), 2006 (164-5) and 2009 (87-91). For an attempt to show how diffusion/imitation could emerge out of a selective mechanism, see Nolan 2006 (174-76).
7. Turchin does not mention the Indus Valley civilisation here (although he does mention south Asia at p. 138). This is often regarded as exceptional among early large-scale polities, in that it had large urban centres, with writing and a division of labour, but no sign of an elite class (Coningham, 2005, 537).
8. It is perhaps odd that Turchin says here that the centuries around 500 BCE, when mega empires first developed (16), saw an “intensification of warfare”. Elsewhere he says that rates of death in war (41, 171), peaked in “late pre-state” and “early state” farming societies (169), declined as larger societies developed (169, 215, 218), and further declined "during and after the Axial Age" (221). Perhaps he is using “intensity” here to refer to something other than rates of death in war (and other than he seems to mean at 38, 167 and 173). Or perhaps this merely illustrates that the decline in warfare was, as he says, not a smooth, linear decline.
References
Coningham, Robin 2005, ‘South Asia: From Early Villages to Buddhism’, in Scarre 2005a.
Diamond, Jared 1998, Guns, Germs and Steel: A Short History of Everybody for the Last 13,000 Years, London: Vintage.
Harris, Marvin 1978, Cannibals and Kings: The Origins of Cultures, London: Collins.
Johnson, Allen and Timothy Earle 2000, The Evolution of Human Societies: From Foraging Group to Agrarian State, Stanford: Stanford University Press.
Lewis, Simon and Mark Maslin 2018, The Human Planet: How We Created the Anthropocene, Harmondsworth: Penguin.
Milner, George 2005, ‘Complex Societies of North America’, in Scarre 2005a.
Morris, Ian 2010, Why the West Rules – For Now: The Patterns of History, and What They Reveal About the Future, London: Profile Books.
Morris, Ian 2013, The Measure of Civilisation: How Social Developmen Decides the Fate of Nations, London: Profile Books.
Morris, Ian 2014, War: What is it Good For? The Role of Conflict in Civilisation, from Primates to Robots, London: Profile Books.
Nolan, Paul 1993, Natural Selection and Historical Materialism, Watford: Glenfield Press.
Nolan, Paul 2002a, ‘What’s Darwinian about Historical Materialism? A Critique of Levine and Sober’, Historical Materialism, 10, 2: 143-169.
Nolan, Paul 2002b, ‘A Darwinian Historical Materialism’, in Historical Materialism and Social Evolution, edited by Paul Blackledge and Graeme Kirkpatrick, Basingstoke: Palgrave Macmillan.
Nolan, Paul 2003, ‘Levine and Sober: A Rejoinder’, Historical Materialism, 11, 3: 177-181.
Nolan, Paul 2006, ‘Why Jerry Cohen Can’t Appeal to Charles Darwin to Help Him Defend Karl Marx (But Why Others Can)’, Science & Society, 70, 2: 155-179.
Nolan, Paul 2009, ‘Diffusion and Intentionality in a Darwinian Historical Materialism’, Science & Society, 73, 1: 84-97.
Pettitt, Paul 2005, ‘The Rise of Modern Humans’, in Scarre 2005a.
Scarre, Chris (ed.) 2005a, The Human Past: World Prehistory & the Development of Human Societies, London: Thames and Hudson.
Scarre, Chris 2005b, ‘The World Transformed: From Foragers and Farmers to States and Empires’, in Scarre 2005a.
Sober, Elliott 1984, The Nature of Selection: Evolutionary Theory in Philosophical Focus, London: University of Chicago Press.
Sober, Elliott 1993, Philosophy of Biology, Oxford: Oxford University Press.
Turchin, Peter 2016, Ultrasociety: How 10,000 Years of War Made Humans the Greatest Cooperators on Earth, Connecticut: Beresta Books.