Are women's sexual preferences for men's facial hair associated with their testosterone during the menstrual cycle?

Abstract

The ovulatory shift hypothesis proposes that women's mate preferences for androgen-dependent secondary sexual traits in men are most pronounced during the ovulatory phase of the menstrual cycle. Using an appropriately powered within-subjects design, we provide the first test of whether women's sexual preferences for male facial hair, which is reliably associated with male sexual maturity and masculinity, peak during the ovulatory phase among women with higher salivary testosterone. Sixty-five heterosexual women completed the study, which included a two-alternative forced choice preference test wherein participants selected the face they found most sexually attractive from pairs of composite images of the same men when fully bearded and when clean-shaven. The task was completed among the same participants during the follicular, ovulatory (validated by the surge in luteinizing hormone) and luteal phases. Participants also provided saliva samples for subsequent assaying of testosterone. We ran two models, both of which showed strong preferences among women for bearded over clean-shaven composite faces. In our first model, women's preferences for bearded faces were negatively associated with their salivary testosterone levels. In our second model, in which we included women's menstrual cycle phase, this negative association appeared to be driven by preferences among women in the ovulatory and follicular phases. However, the main effect of cycle phase and the interaction between testosterone and cycle phase were not statistically significant. Although further replication is required to confirm our findings, for the present we conclude that women's preferences for men's beardedness may not be related to changes in their salivary testosterone over the menstrual cycle in ways that support the ovulatory shift hypothesis.