According to this view, the incest taboo is not necessarily universal, but is likely to arise and become more strict under cultural circumstances that favour exogamy over endogamy, and likely to become more lax under circumstances that favor endogamy. This hypothesis has also achieved some empirical support. While it is theoretically possible that natural selection may, under certain genetic circumstances, select for individuals that instinctively avoid mating with (close) relatives, incest will still exist in the gene pool because even genetically weakened, inbred individuals are better watchposts against predators than none at all, and weak individuals are useful for the stronger individuals in the group as looking out for predators without being able to seriously compete with the stronger individuals. Additionally, protecting the health of closer relatives and their inbred offspring is more evolutionarily advantegous than punishing said relative, especially in a context where predation and starvation are significant factors, as opposed to a rich welfare state. This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources.

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