The scent of symmetry: A human sex pheromone that signals fitness?

A previous study by the authors showed that the body scent of men who have greater body bilateral symmetry is rated as more attractive by normally ovu lating (non-pill-using) women during the period of highest fertility based on day within the menstrual cycle. Women in low-fertility phases of the cyc le and women using hormone-based contraceptives do not show this pattern, T he current study replicated these findings with a larger sample and statist ically controlled for men's hygiene and other factors that were not control led in the first study. The current study also examined women's scent attra ctiveness to men and found no evidence that men prefer the scent of symmetr ic women. We propose that the scent of symmetry is an honest signal of phen otypic and genetic quality in the human male, and chemical candidates are d iscussed, In both sexes, facial attractiveness (as judged from photos) appe ars to predict body scent attractiveness to the opposite sex. Women's prefe rence for the scent associated with men's facial attractiveness is greatest when their fertility is highest across the menstrual cycle. The results ov erall suggest that women have an evolved preference for sires with good gen es. (C) 1999 Elsevier Science Inc.