The incest taboo?

Abstract

The ongoing discussion between social scientists who espouse some variety of socio-environmental theory (for examples see Leavitt, Incest and Inbreeding Avoidance: A Critique of Darwinian Social Science, 2005: 215 and Leavitt, `Disappearance of the Incest Taboo', American Anthropologist, 1989) and those who advance Darwinian selection principles (human sociobiology, Darwinian social science, behavioral genetics, or evolutionary psychology) have often focused their debate on the incest taboo and the avoidance of inbreeding. Acknowledged by many as an important cultural universal, the incest taboo has commonly been recognized by Darwinian social scientists as the most compelling instance supporting the premise that complex human behaviors can result from natural selection. Human sociobiology forwards the argument that natural selection mechanisms will favor outbreeding because inbreeding is deleterious. By contrast, socio-environmentalists have made the case that the incest taboo is a socioculturally derived solution to important practical problems found in human social life. In this article, I not only challenge the commonly held notion that inbreeding is injurious, but also argue that inbreeding is often harmless and even fitness-enhancing. If so, Westermarck's hypothesis that children raised together naturally trigger selection mechanisms for sexual avoidance is highly questionable. Rather, incest and inbreeding avoidance are diverse practices related to environmental circumstances.