Darwinian anthropology
Darwinian anthropology describes an approach to anthropological analysis which employs various theories from Darwinian evolutionary biology. Whilst there are a number of areas of research that can come under this broad description some specific research projects have been closely associated with the label. A prominent example is the project that developed in the mid 1970s with the goal of applying sociobiological perspectives to explain patterns of human social relationships, particularly kinship patterns across human cultures.
This kinship-focused Darwinian anthropology was a significant intellectual forebear of evolutionary psychology, and both draw on biological theories of the evolution of social behavior upon which the field of sociobiology was founded.
Overview
In 1974 the biologist Richard D. Alexander published an article The Evolution of Social Behavior which drew upon W.D.Hamilton's work on inclusive fitness and kin selection and noted that:Amongst other suggestions, Alexander suggested that certain patterns of social cooperation documented by ethnographers, in particular the avunculate relationship, could be explained in reference to individuals pursuing a strategy of individual inclusive fitness maximization under conditions of low certainty-of-paternity. This hypothesis was subsequently taken up and elaborated in a series of studies by other Darwinian anthropologists:
Ultimately these analyses were considered unsuccessful, and were specifically criticized by other sociobiologists on a number of grounds. One problem was said to be that interpreting inclusive fitness theory to imply that individuals have evolved the characteristic of pursuing strategies to maximize their own 'inclusive fitness' is erroneous; the theory should instead be interpreted to describe selection pressures on genes:
A related problem was that, in assuming that individuals simply operate as inclusive fitness maximizing agents, any investigation of the proximate psychological mechanisms that mediate social behaviors was ignored. Symons made this observation in his 1989 Critique of Darwinian Anthropology:
Symons, along with Tooby and Cosmides, were amongst the founders of the emerging school of evolutionary psychology, whose aim has been to focus more on these hypothesized proximate psychological mechanisms.
Theoretical background
Darwinian anthropology was critiqued by Symonds for its agnosticism as to the psychological mechanisms governing how social behavior is actually expressed in the human species, and its reliance on interpreting inclusive fitness theory to simply imply that humans have evolved to be inclusive fitness maximizers. This section will review some of the relevant background discussion in inclusive fitness theory to clarify why this position was considered untenable.Evolutionary versus proximate explanations
Inclusive Fitness theory has often been interpreted to mean that social behavior per se is a goal of evolution, and also that genes are selected to find ways of actively distinguishing the identity of close genetic relatives ‘in order to’ engage in social behaviors with them.The apparent rationale for this common mis-interpretation is that organisms would thereby benefit the “Inclusive Fitness of the individuals involved”. This approach overlooks the point that evolution is not a teleological process, but a passive, consequential and undirected biological process, where environmental variations and drift effects are present alongside random gene mutations and natural selection.
Inclusive fitness theory takes the form of an ultimate explanation, specifically a criterion, for the evolution of social behaviors, not a proximate mechanism governing the expression of social behaviors. What forms of social behavior might meet this criterion are cannot be a priori specified by the theory, nor can it shed light on whether the life history of a species provides opportunities for social interactions to occur. Thus, strictly speaking, the interpretation that organisms ‘have evolved to’ direct social behavior towards genetic relatives is not implied by the theory.
Investigating how inclusive fitness theory might apply to the potential emergence of social traits in any given species must begin with an analysis of the evolutionarily typical ecological niche, demographics, and patterns of interaction of that species. Where significant interaction between individuals is not present in the life history of a species, the theory is necessarily null regarding social behaviors between individuals. As Silk put it;
Consideration must thus be given to whether the ecological niche leads to the clustering of individuals in groups or whether individuals are typically solitary. Socioecology research, for example, suggests that fundamental influences on demographic patterns are the distribution/fecundity of primary food sources as well as patterns of predation. When considering social behavior traits of a given species, consideration of these influences is in a sense, logically prior to analyses of inclusive fitness pressures on the species.
Selection pressure on genes or strategy of individuals
Darwinian anthropology, following R. D. Alexander, used the notion of the inclusive fitness of individuals rather than the inclusive fitness of genes. Dawkins pointed to this as an error. The source of the confusion can be traced to discussions in Hamilton's early papers on inclusive fitness. In his 1963 paper Hamilton refers, unambiguously, to selection pressures on genes;However, in his paper published in 1964, actually written before the 1963 paper, Hamilton had included a subsidiary discussion on what the genetic theory might imply for how we look at the fitness of individuals:
It is clear here that the formal treatment is of the selection pressures on types, whilst the notion of individual inclusive fitness may serve as a guide to the adaptiveness of the trait; just as consideration of effects of a trait on an individual's fitness can be instructive when considering classical selection on traits. At the same time, it is understandable that Alexander took the inclusive fitness of individuals as a heuristic device.
Context-based or discrimination-based expression mechanisms
In his 1964 paper, Hamilton 'hazards' “the following unrigorous statement of the main principle that has emerged from the model”;He uses the terms 'hazards', 'unrigorous', and 'will seem' deliberately, since his formal analysis makes clear that the model specifies the evolutionary selection pressure, rather than specifying what mechanisms govern the proximate expression of social behaviors. He also clearly points to social behaviors being evoked in distinct situations, and that individuals may encounter potential social recipients of different degree of relationship in different situations. If one ignores the cautious qualifying words however, the passage might readily be interpreted to imply that individuals are indeed expected to make an active assessment of the degree of relatedness of others they interact with in different situations. Later in the paper, Hamilton again discusses the issue of whether the performance of social behaviors might be conditional on; discriminating factors which correlate with close relationship with the recipient, or actually discriminating which individuals 'really are' in close relationship with the recipient:
For certain social behaviors, Hamilton suggests there may be selection pressure for more discerning discrimination of genetic relatedness, were the mutation to occur. But 'in fact' the same net result of accurately targeting social behaviors towards genetic relatives could be achieved via a simpler mechanism of being expressed in proximity to the actor's 'home'. Hamilton is thus agnostic as to whether evolved social behaviors might be expressed via straightforward proximate mechanisms such as location-based cues, or whether more specific discriminatory powers might govern their expression. He does suggest that the distinct social contexts within which various social behaviors are expressed are factors to consider. Other theorists have discussed these questions of whether proximity, context or more discriminatory expression may govern behaviors:
Dawkins believes social behaviors will in practice be governed by context-based expression. Maynard Smith is, like Hamilton, agnostic, but reiterates the point that context-based cues might well govern their expression and that actively distinguishing relatives is not necessarily expected for the expression of those social traits whose evolution is governed by inclusive fitness criteria. In sum, inclusive fitness theory does imply that; the evolutionary emergence of social behavior can occur where there is statistical association of genes between social actors and recipients; but that the expression of such evolved social behaviors is not necessarily governed by actual genetic relatedness between participants. The evolutionary criterion and the proximate mechanism must thus not be confused: the first does require genetic association, the second does not.
Darwinian anthropology's central premise that human behavior has evolved to maximize the inclusive fitness of individuals is thus not a logical derivative of the theory. Also, the notion that humans will discriminate social behaviors towards genetic relatives is again not entailed by the theory.
Reception by anthropologists
Before the questions raised within anthropology about the study of ‘kinship’ by Schneider and others from the 1960s onwards, anthropology itself had paid very little attention to the notion that social bonds were anything other than connected to consanguinal relatedness. The social bonding associated with provision of and sharing of food was one important exception, particularly in the work of Richards, but this was largely ignored by descriptions of ‘kinship’ till more recently. Although questioning the means by which ‘kinship bonds’ form, few of these early accounts questioned the fundamental role of ‘procreative ties’ in social bonding. From the 1950s onwards, reports on kinship patterns in the New Guinea Highlands added some momentum to what had until then been only occasional fleeting suggestions that living together might underlie social bonding, and eventually contributed to the general shift away from a genealogical approach. For example, on the basis of his observations, Barnes suggested:Similarly, Langness' ethnography of the Bena Bena also emphasized a break with the genealogical perspective:
By 1972, Schneider had raised deep problems with the notion that human social bonds and 'kinship' was a natural category built upon genealogical ties, and especially in the wake of his 1984 critique this has become broadly accepted by most, if not all, anthropologists.
The darwinian anthropology perspectives, arising in the early 1970s, had not unreasonably assumed that the genealogical conceptions of human kinship, in place since Morgan's early work in the 1870s, were still valid as a universal feature of humans. But they emerged at precisely the time that anthropology, being particularly sensitive about its own apparent 'ethnocentric' generalizations about kinship was seeking to distance itself from these conceptions. The vehemence of Sahlins' rebuttal of sociobiology's genetic relatedness perspective in his 1976 The use and abuse of Biology, which underlined the non-genealogical nature of human kinship, can be understood as part of this 'distancing' trend.