On Sociobiological Theory and the Cheyenne Case

Moore (CA 3I:322-30) sees the Cheyenne case as conclusive demonstration that sociobiological principles do not apply to the human species. His claim is based on the existence in Cheyenne society of two types of chiefs: "peace chiefs," who largely avoided combat, led the tribe for decades, married polygamously, and inherited their status from their fathers, and "war chiefs," who voluntarily devoted themselves to war, regarded it as honourable to die before their terms of office were over, and often took vows of celibacy. He shows that war chiefs had significantly shorter life spans and (probably) fewer offspring than peace chiefs and that, given these characteristic demographic traits, a "gene" for aggressiveness (presumed for the sake of argument to underlie war-chief behaviour) would soon be driven to extinction. His specific aim is to falsify the claim that aggressiveness is a human universal trait that has evolved because the more aggressive (i.e., warlike) males sire significantly more offspring. While the evidence Moore adduces undoubtedly addresses issues of substantive concern and interest, little of it has any bearing on sociobiological questions. Since misinterpretations of evolutionary theory of this kind are surprisingly common, I take this opportunity to try and clarify matters. I am in no way seeking to defend any of the propositions that Moore is concerned to disprove, nor am I concerned to engage in personal polemics. I am simply concerned with what evolutionary biology would actually have to say about the Cheyenne and what kinds of evidence are necessary to test the predictions that arise from these considerations. Ingold (I986) has pointed out that, during the heyday of evolutionary anthropology, anthropologists' understanding of evolution was very different from that of biologists, mainly because their conception of evolution was derived from a Spencerian rather than a Darwinian perspective. The continuing debate over sociobiology suggests that analogous problems are still clouding the issues, thereby preventing a proper integration of evolutionary biology and social anthropology to their mutual benefit. Criticisms of sociobiology commonly involve three classic errors: (i) taking the "genes" in sociobiological explanations literally, (2) conflating ontogenetic and functional explanations, and (3) misinterpreting the biological statuses of two different behavioral strategies. In evolutionary biology (following conventional usage in population genetics), the term "geine" strictly speaking refers to a trait or character and not to a segment of DNA. Indeed, Darwinian explanations of evolutionary change do not depend on the existence of DNA. It has repeatedly been pointed out that the term "heritability" in the Darwinian formula (see Dunbar i98.2a) refers to fidelity of copying (see, e.g., Dawkins I976, I983). DNA happens to be a form of inheritance mechanism with which we are particularly familiar, but it is by no means the only one. Cultural transmission of learned behaviour patterns also involves the inheritance of traits between individuals (some of whom may be genetically unrelated to each other). It is the recognition of this that has led to the considerable interest among evolutionary biologists in the development of models of cultural evolution, since these systems are DNA-free but still subject to the Darwinian processes of natural selection (see, e.g., Cavalli-Sforza and Feldman I98I, Boyd and Richerson i985). Hence, in the present case, the proper traits for comparison are the strategies "peace-chief" and "war-chief," not "a gene for aggressiveness" and "a gene for nonaggressiveness. " For purely heuristic reasons, sociobiologists commonly use the shorthand "suppose a gene for peace-chiefness. " Doing so, however, carries no connotation of genetic determination; rather, it is simply a reminder that the proper way to evaluate the evolutionary significance of a trait is in terms of its impact on genetic propagation in future generations (as opposed to the survival of the individual, the group, or the species). (Many early articles in animal sociobiology often carried a footnote to this effect, but most of those working in this field now simply take it as given.) If "war chief" is a cultural "meme" (in Dawkins's sense), then an attempt to relate it either to a gene for "aggression" or to the reproductive performance of war chiefs themselves is irrelevant-the first because memes are independent of the biology of the individuals whose bodies (? brains) they currently occupy, the second because what matters is the success with which the meme "war chief" is propagated in successive generations, not the success with which the individual bodies bearing the "war-chief" meme reproduce. (The whole point of memes is that their interests may conflict with the interests of the i. Permission to reprint items in this section may be obtained only from their authors.