This article defends a version of the Westermarck Effect, integrating existing clinical, biological, and philosophical dimensions to incest avoidance. By focusing on care-based attachment in primates, my formulation of the effect suggests the power of a phylogenetic argument widely accepted by primatologists but not by cultural anthropologists. Identifying postadoption incest as a phenomenon with underexplored evidential value, the article sketches an explanatory strategy for reconciling the effect with the clinical reality of incest, concluding with an explicit argument against culture-first (...) or conventionalist accounts of incest avoidance prevalent in anthropology. (shrink)

The Westermarck Effect posits that intimate association during childhood promotes human incest avoidance. In previous work, I articulated and defended a version of the Westermarck Effect by developing a phylogenetic argument that has purchase within primatology but that has had more limited appeal for cultural anthropologists due to their commitment to conventionalist or culture-first accounts of incest avoidance. Here I look to advance the discussion of incest and incest avoidance beyond culture-first accounts in two ways. First, I shall (...) dig deeper into the disciplinary grooves within cultural anthropology that make attractive the view that incest has a naturalness to it that is countered only or primarily by explicit social rules, such as taboos. Second, I further explore the emerging, post-conventionalist view of incest avoidance in a more positive vein by elaborating on the nature of the Westermarckian mechanism and how it relates to such explicit social rules and our innate biological endowments. One general aim here is to overcome the bifurcation between perspectives that are seen as biological and those seen as cultural, preempting or countering the claim that rejecting culture-first accounts entails a form of biological reductionism, a general aim I have pursued in related publications on bioessentialism about kinship. (shrink)

According to Westermarck’s widely accepted explanation of the incest taboo, cultural prohibitions on sibling sex are rooted in an evolved biological disposition to feel sexual aversion toward our childhood coresidents. Bernard Williams posed the “representation problem” for Westermarck’s theory: the content of the hypothesized instinct is different from the content of the incest taboo —thus the former cannot be causally responsible for the latter. Arthur Wolf posed the related “moralization problem”: the instinct concerns personal behavior whereas the prohibition (...) concerns everyone. This paper reviews possible ways of defending Westermarck’s theory from the representation and moralization problems, and concludes that the theory is untenable. A recent study purports to support Westermarck’s account by showing that unrelated children raised in the same peer groups on kibbutzim feel sexual aversion toward each other and morally oppose third-party intra-peer-group sex, but this study has been misinterpreted. I argue that the representation and moralization problems are general problems that could potentially undermine many popular evolutionary explanations of social/moral norms. The cultural evolution of morality is not tightly constrained by our biological endowment in the way some philosophers and evolutionary psychologists believe. (shrink)

What explains the distinctive features of human behavior? In this book, Stewart-Williams aims to answer this ambitious question. This book is an engaging addition to the already long list of recent attempts to provide an evolutionary explanation of human uniqueness. It is organized into six chapters, plus two appendices. These chapters address several key topics in evolutionary theory, sex differences and sexual behavior, altruism, and cultural evolution, albeit with varying degrees of detail and depth. These topics include sexual selection, kin (...) selection, Hamilton’s rule, reciprocal altruism, costly signaling theory, group selection, gene-centered views of evolution, inclusive fitness, proximate and ultimate evolutionary explanations, inbreeding avoidance, the Westermarck effect, jealousy, sperm competition, mating and parenting effort, cumulative cultural evolution, imitation and learning biases, evolutionary mismatch theories, and more. (shrink)