MENSTRUAL-CYCLE VARIATION IN WOMENS PREFERENCES FOR THE SCENT OF SYMMETRICAL MEN

Evidence suggests that female sexual preferences change across the men strual cycle. Women's extra-pair copulations tend to occur in their mo st fertile period, whereas their intra-pair copulations tend to be mor e evenly spread out across the cycle. This pattern is consistent with women preferentially seeking men who evidence phenotypic markers of ge netic benefits just before and during ovulation. This study examined w hether women's olfactory preferences for men's scent would tend to fav our the scent of more symmetrical men, most notably during the women's fertile period. College women sniffed and rated the attractiveness of the scent of 41 T-shirts worn over a period of two nights by differen t men. Results indicated that normally cycling (non-pill using) women near the peak fertility of their cycle tended to prefer the scent of s hirts worn by symmetrical men, Normally ovulating women at low fertili ty within their cycle, and women using a contraceptive pill, showed no significant preference for either symmetrical or asymmetrical men's s cent. A separate analysis revealed that, within the set of normally cy cling women, individual women's preference for symmetry correlated wit h their probability of conception, given the actuarial value associate d with the day of the cycle they reported at the time they smelled the shirts. Potential sexual selection processes and proximate mechanisms accounting for these findings are discussed.