Westermarck, Freud, and the incest taboo: does familial resemblance activate sexual attraction?

Evolutionary psychological theories assume that sexual aversions toward kin are triggered by a nonconscious mechanism that estimates the genetic relatedness between self and other. This article presents an alternative perspective that assumes that incest avoidance arises from consciously acknowledged taboos and that when awareness of the relationship between self and other is bypassed, people find individuals who resemble their kin more sexually appealing. Three experiments demonstrate that people find others more sexually attractive if they have just been subliminally exposed to an image of their opposite-sex parent (Experiment 1) or if the face being rated is a composite image based on the self (Experiment 2). This finding is reversed when people are aware of the implied genetic relationship (Experiment 3). These findings have implications for a century-old debate between E. Westermarck and S. Freud, as well as contemporary research on evolution, mate choice, and sexual imprinting.