Effect of Copulins on Rating of Female Attractiveness, Mate-Guarding, and Self-Perceived Sexual Desirability

Olfaction and chemical signaling play an important role in the mating behaviors of many taxa, yet there is minimal empirical research on human putative pheromones. A mixture of five volatile fatty acids secreted vaginally, identified and named “copulins,” significantly increase in concentration during the follicular phase and decrease in concentration during the luteal phase in nonpill using women. Men exposed to copulins exhibit an increase in testosterone, are inhibited in discriminating the attractiveness of women’s faces, and behave less cooperatively. According to Anisogamy, Sexual Selection and Parental Investment Theory, mammalian males, having low cost and high benefit from any copulatory interaction, may adaptively utilize any useful cues to identifying ovulating females and adjust their behavior accordingly in order to maximize their potential reproductive success. In the current study, we attempted a replication of Jütte and Grammer’s finding indicating copulins inhibit the ability of men to discriminate attractiveness of women’s faces, and we examined the role of copulins in self-reported mate-guarding behaviors and self-perceived sexual desirability. We utilized a randomized placebo-controlled design and as predicted, results indicated men exposed to copulins were more likely to rate themselves as sexually desirable to women and, on average, the copulin group rated women’s faces as more attractive than controls. There were no significant findings with mate guarding.