Facial symmetry of the sisters of Thai and Istmo Zapotec androphilic males.

Abstract

Male androphilia (i.e., sexual attraction to adult males) is considered an evolutionary paradox because it reduces direct reproduction but is influenced by genetic factors, reliably occurs across cultures, and has persisted over evolutionary time. The hypergyny hypothesis rests on the premise that the female relatives of androphilic males possess physical traits that signal fertility, such as elevated symmetry. If this premise were true, such traits could help attract reproductive partners with higher socioeconomic status, thereby furnishing resources to produce and sustain multiple offspring. This, in turn, would help females to offset their androphilic male siblings' lack of reproduction. The present study examined whether the sisters of male androphiles have elevated facial symmetry compared with women without androphilic male siblings. Sixty-six women with androphilic male siblings and 271 women without androphilic male siblings were recruited from Thailand and the Istmo region of Oaxaca, Mexico. Results demonstrated no significant differences in facial asymmetry between women with and without androphilic male siblings. In the absence of such a difference, this study, like previous ones, does not support the hypergyny hypothesis as a viable explanation for the evolutionary paradox of male androphilia. Public Significance StatementMales' sexual attraction to females and females' sexual attraction to males is perhaps the largest and most phylogenetically widespread of any psychological sex difference. The occurrence of exclusive male same-sex sexual attraction in most human cultures deviates from this common pattern. The present study is significant because it attempts to elucidate the evolutionary basis of male same-sex sexual attraction-a trait that has long perplexed evolutionists.