1. I have long assumed that Darwinian Historical Materialism (DHM) involved a form of group selection. This did not bother me unduly, partly because the theory did seem to explain what are surely the main trends of human history.(1) The work of Elliott Sober and David Sloan Wilson (1999) had also helped reconcile me to the notion of group selection.
Group selection, moreover, seems to be invoked elsewhere in the human sciences without generating howls of outrage, or indeed much controversy at all. There is, after all, a powerful and influential account of how the capitalist market economy encourages increasing productivity by “selecting” the more efficient firms as the less efficient go out of business. Given that firms are groups of individuals, this seems to involve a form of group selection. (And to the extent that the variation between firms is random with respect to survivability, then this “evolutionary theory of the firm” is even more like the selective process that DHM suggests.)(2)
Even Richard Dawkins (1989, 263) has said that “increasing the ratio of between-group variation to within-group variation” can make possible a form of group selection. And the human species has developed a range of political and legal institutions (“superstructures” in the terminology of Marxism) and ideologies (usually, though not always, religious ideologies) that serve to increase individual conformity to group norms (or elite requirements). Moreover, there is likely to be a significantly lower rate of exchange of cultural traits between groups than within groups, simply as a result of proximity. Perhaps the combined effect of these phenomena is to increase the ratio of between-group variation to within-group variation to the point where even Dawkins would accept that a form of group selection is possible in human society and history, and perhaps even a common occurrence.
(I see no obvious reason to think, incidentally, that group selection is inconsistent with a sophisticated methodological individualism, in which the characteristics of groups can be described, perhaps even explained, in terms of individuals and their properties (including their relational properties). It is fairly clear how this could be true of firms, for instance.)
There is a second possibility, however. DHM does involve group selection in its present formulations, but this is simply a reflection of an early, immature phase of its development. There was, after all, no explicit and rigorous distinction between individual and group selection in Darwinism proper until the publication of G. C. Williams’s Adaptation and Natural Selection in 1966 (Dawkins, 1989, ix-x; Sober and Wilson, 1999, 5). It might be possible in the future, therefore, to formulate Darwinian historical materialist explanations in terms of individual level selection. It would be unwise, meanwhile, to reject progress in applying Darwinian logic to explanations of the long-term trends and large-scale patterns of human history simply because those explanations initially happened to be formulated in terms of group selection. Why make the best an enemy of the good (or at least of the better)?
And there is a third possibility. DHM may not involve group selection at all, even temporarily. Dawkins (2006, 199-200) quotes a well-known passage from Darwin in which the great man describes what seems to be a process of group selection:
When two tribes of primeval man, living in the same country, came into competition, if the one tribe included (other circumstances being equal) a greater number of courageous, sympathetic, and faithful members, who were always ready to warn each other of danger, to aid and defend each other, this tribe would without doubt succeed best and conquer the other… Selfish and contentious people will not cohere, and without coherence nothing can be effected. A tribe possessing the above qualities in a high degree would spread and be victorious over other tribes; but in the course of time it would, judging from all past history, be in turn overcome by some other and still more highly-endowed tribe.
Perhaps surprisingly, Dawkins (2006, 200) does not regard this hypothetical example as describing a process of group selection, as he explains in a passage specifically addressed to “biological specialists”:
To satisfy any biological specialists who might be reading this, I should add that Darwin’s idea was not strictly group selection, in the true sense of successful groups spawning daughter groups whose frequency might be counted in a metapopulation of groups. Rather, Darwin visualized tribes with altruistically cooperative members spreading and becoming more numerous in terms of numbers of individuals. Darwin’s model is more like the spread of the grey squirrel in Britain at the expense of the red: ecological replacement, not true group selection.
Now, whether Darwin’s example involves group selection or not, it describes a process relevantly similar to the one DHM suggests. So perhaps DHM also involves “ecological replacement” rather than group selection.
Kuznar and Sanderson (2006, 8), respectively an anthropologist and a sociologist who are also critical of group selection, echo Dawkins’s view, saying that “the defeat in war of one tribe by another is not a genuine form of group selection.” Perhaps not. But to the extent that the victory is explained by between-tribe variations, and that the variants possessed by the victorious tribe increase their representation in the “metapopulation” of tribes as a result of the victory, then it is some form of selection. If this is not group selection, it is presumably a complex form of individual selection that merely appears to be group selection. And Dawkins’s “ecological replacement” is also, presumably, a form of individual selection that can seem to be group selection. So DHM, too, might involve a form of individual selection, and only appear to involve group selection.
2. I must admit that I am not entirely convinced by Dawkins’s claim that Darwin’s example involves ecological replacement rather than group selection. (I wonder if he was so desperate to absolve Darwin of the sin of group selection that Dawkins did not fully think this through.) It is not even clear to me that “ecological replacement” is an evolutionary mechanism akin to, or a version of, individual selection. I suspect that ecological replacement is an effect, and group selection is a process (though not the only one) that can bring about that effect.
Moreover, it seems to me that Darwin’s example, even if we choose to regard it as something other than group selection, is vulnerable to one of the criticisms that Dawkins makes of group selection. Indeed, it is just as vulnerable to this criticism as is the example of group selection that Dawkins provides in order to illustrate the weaknesses of group selection. To demonstrate this, we can begin by examining what we might call Dawkins’s (2006, 198-9) “free-rider” objection to group selection:
A tribe with a stirringly belligerent ‘god of battles’ wins wars against rival tribes whose gods urge peace and harmony, or tribes with no gods at all. Warriors who unshakeably believe that a martyr’s death will send them straight to paradise fight bravely, and willingly give up their lives. So tribes with this kind of religion are more likely to survive in inter-tribal warfare, steal the conquered tribe’s livestock and seize their women as concubines. Such successful tribes prolifically spawn daughter tribes, all worshipping the same tribal god…
When it [group selection] is pitted against selection at lower levels – as when group selection is advanced as an explanation for individual self-sacrifice – lower-level selection is likely to be stronger. In our hypothetical tribe, imagine a single self-interested warrior in an army dominated by aspiring martyrs eager to die for their tribe and earn a heavenly reward. He will be only slightly less likely to end up on the winning side as a result of hanging back in the battle to save his own skin. The martyrdom of his comrades will benefit him more than it benefits each one of them on average, because they will be dead. He is more likely to reproduce than they are, and his genes for refusing to be martyred are more likely to be reproduced into the next generation. Hence tendencies towards martyrdom will decline in future generations.
This example, that Dawkins presents as an example of group selection, is very similar, indeed almost identical, to the example from Darwin that Dawkins wants to claim as “ecological replacement” rather than “genuine group selection.” And Darwin’s example, too, would seem to be vulnerable to the objection that is raised here by Dawkins against “genuine” group selection, that of “subversion from within” (Dawkins, 2006, 199) by deviant “free riders.”
To see this, let us repeat Dawkins’s criticism of group selection but substitute some phrases from Darwin’s example:
When group selection is pitted against selection at lower levels – as when group selection is advanced as an explanation for individual self-sacrifice – lower-level selection is likely to be stronger. In Darwin’s hypothetical tribe, imagine a single self-interested warrior in an army dominated by courageous, sympathetic, and faithful members willing to die for their tribe. He will be only slightly less likely to end up on the winning side as a result of hanging back in the battle to save his own skin. The self-sacrifice of his comrades will benefit him more than it benefits each one of them on average, because some of them will be dead. He is more likely to reproduce than they are, and his genes for refusing to be courageous, sympathetic, and faithful are more likely to be reproduced into the next generation. Hence tendencies towards courage, sympathy, and fidelity will decline in future generations.
It should be apparent from this passage that Dawkins’s free-rider criticism of group selection is just as effective against Darwin’s example.
In this respect, Darwin’s example seems to be very different to the “ecological replacement” of red squirrels by grey squirrels that Dawkins says is so similar. After all, it is difficult to see what free riding would involve for grey squirrels, and how it would enhance their reproductive success relative to other grey squirrels. (If, however, someone suggested that grey squirrels had replaced red squirrels by forming more cooperative groups than red squirrels, then the free-rider criticism might be relevant in that case too.)
This difference in vulnerability to the free-rider criticism is presumably because the members of both of these hypothetical human groups, unlike the squirrels, are engaged in a collective activity (warfare), in which the success of each (individually) is conditional upon the success of all (collectively). So, if the collective is successful, the individual reaps the (reproductive) benefits regardless of his contribution to that success, hence the opportunity for free riding. Nothing like this seems to be true of the squirrel example.(3)
So Dawkins’s distinguishing between ecological replacement and group selection, and describing Darwin’s example as the former, does not seem to rescue Darwin’s example from the free-rider criticism.
But perhaps we do not need to label Darwin’s example as “ecological replacement” in a (probably unsuccessful) attempt to save it from the free-rider problem after all. As Sober and Wilson (1999, 18-30) show, in a population of competing groups, it is possible that the proportion of self-sacrificing individuals within each group will decline, but the proportion of self-sacrificing individuals within the population as a whole will increase, if the reproductive success of the groups containing more such individuals is sufficiently higher than the reproductive success of the groups containing fewer such individuals. Dawkins (2006, 199) would probably disagree, but such conditions may be quite common in nature.
3. Dawkins (2006, 200) says that the process described by Darwin is “not strictly group selection in the true sense” because it does not involve “successful groups spawning daughter groups whose frequency might be counted in a metapopulation of groups.” But surely Darwin’s process must involve just this. After all, given fairly obvious constraints on group size, successful groups are hardly likely to expand indefinitely without fissioning into smaller groups. Two pages earlier in his discussion of group selection, Dawkins (2006, 198) cites favourably Napoleon Chagnon’s work on the Yanomamo of the Venezuelan Highlands whose villages “fission” in just this way:
The idea of a group spawning daughter groups, like a beehive throwing off swarms, is not implausible, by the way. The anthropologist Napoleon Chagnon mapped just such fissioning of villages in his celebrated study of the ‘Fierce People,’ the Yanomamo of the South American jungle.
But, if there is between-group variation here, leading to “differential spawning success,” so to speak, and if these variations are “inherited” by daughter groups, then it seems quite possible that, at least among the Yanomamo, “group selection in the true sense of successful groups spawning daughter groups” actually occurs. This might involve the group-selection of non-altruistic behaviours as well as altruistic behaviours (Sober and Wilson, 1999, 30-1). (And the fact that Chagnon himself does not accept group selection is polemically irrelevant here.)
4. I am happy, however, to put such doubts aside, to bow to the expertise of others in this area, and to accept that the military victory of one tribe over another is not group selection (Kuznar and Sanderson), and that even the (ecological) replacement of one tribe by another is not group selection (Dawkins). I am happy to do so because anybody who criticises DHM for relying upon group selection can then be told that it is merely ecological replacement, which they had foolishly misinterpreted as group selection.
So there are, it seems to me, three possibilities that I can be relaxed about: first, DHM does rely upon group selection, but group selection is acceptable in theory and common in practice; second, DHM, as presently formulated, invokes group selection, group selection is unacceptable, but DHM could in the future be reformulated in terms of individual selection; or, third, DHM does not rely upon group selection but, instead, upon ecological replacement.
There is, of course, a fourth possibility that I am less relaxed about, that DHM does rely upon group selection, and that group selection is unlikely in theory and uncommon in practice.
I am committed to the defence of DHM, but I have no existential commitment to group selection. If DHM necessarily involves group selection, then I will hope that group selection is defensible. If it is not defensible, and DHM cannot be formulated in a way that avoids group selection, then DHM fails.
But I am not at present convinced either that DHM depends upon group selection or that group selection is indefensible.
ENDNOTES
REFERENCES
Dawkins, Richard. 1989. The Selfish Gene. Oxford: Oxford University Press.
Dawkins, Richard. 2006. The God Delusion. London: Transworld Publishers.
Kuznar, Lawrence A. and Stephen K. Sanderson. 2007. “The Potentials and Challenges of Cultural Materialism.” In Kuznar and Sanderson eds., Studying Societies and Cultures: Marvin Harris’s Cultural Materialism and its Legacy. Boulder: Paradigm Publishers.
Sober, Elliott and David Sloan Wilson. 1999. Unto Others: The Evolution and Psychology of Unselfish Behaviour. London: Harvard University Press.