Kin Selection - Kin Selection and Human Social Patterns

Kin Selection and Human Social Patterns

See also: Darwinian anthropology and Nurture kinship

Evolutionary psychologists, following Darwinian anthropologists' interpretation of kin selection theory initially attempted to explain human altruistic behavior through kin selection by stating that "behaviors that help a genetic relative are favored by natural selection." However, most Evolutionary psychologists recognize that this common short-hand formulation is inaccurate;

any misunderstandings persist. In many cases, they result from conflating "coefficient of relatedness" and "proportion of shared genes," which is a short step from the intuitively appealing—but incorrect—interpretation that "animals tend to be altruistic toward those with whom they share a lot of genes." These misunderstandings don’t just crop up occasionally; they are repeated in many writings, including undergraduate psychology textbooks—most of them in the field of social psychology, within sections describing evolutionary approaches to altruism. (Park 2007, p860)

As with the earlier sociobiological forays into the cross-cultural data, typical approaches are not able to find explanatory fit with the findings of ethnographers insofar that human kinship patterns are not necessarily built upon blood-ties. However, as Hamilton's later refinements of his theory make clear, it does not simply predict that genetically related individuals will inevitably recognise and engage in positive social behaviours with genetic relatives: rather, indirect context-based mechanisms may have evolved, which in historical environments have met the inclusive fitness criterion (see above section). Consideration of the demographics of the typical evolutionary environment of any species is crucial to understanding the evolution of social behaviours. As Hamilton himself puts it, "Altruistic or selfish acts are only possible when a suitable social object is available. In this sense behaviours are conditional from the start." (Hamilton 1987, 420).

Under this perspective, and noting the necessity of a reliable context of interaction being available, the data on how altruism is mediated in social mammals is readily made sense of. In social mammals, primates and humans, altruistic acts that meet the kin selection criterion are typically mediated by circumstantial cues such as shared developmental environment, familiarity and social bonding. That is, it is the context that mediates the development of the bonding process and the expression of the altruistic behaviours, not genetic relatedness per se. This interpretation thus is compatible with the cross-cultural ethnographic data and has been called nurture kinship.