ASYMMETRY AND HUMAN FACIAL ATTRACTIVENESS - SYMMETRY MAY NOT ALWAYS BE BEAUTIFUL

It has been postulated that levels of fluctuating asymmetry in human f aces may be negatively related to components of fitness such as parasi te-resistance; hence potential mates with low levels of asymmetry may appear more attractive. However, previous investigations of the relati onship between asymmetry and facial attractiveness have confounded man ipulations of asymmetry with facial 'averageness' and mean trait size. In this experiment we performed a manipulation that altered asymmetry within a face without altering the mean size of facial features. Thes e faces were then rated on attractiveness. Contrary to what was predic ted, faces that were made more symmetrical were perceived as being les s attractive. These results do not support the hypothesis that attract iveness is related to low levels of fluctuating asymmetry. The observe d positive relationship between asymmetry and facial attractiveness ma y be because certain facial features (including those contributing to attractiveness) in fact show directional asymmetry or antisymmetry. Ou r manipulations thus render naturally asymmetric features symmetrical. This may make symmetric faces less attractive because of the reductio n of natural directional asymmetries, perhaps making the faces appear unemotional. The role of fluctuating asymmetries alone in assessments of facial beauty is still unknown, although this experiment suggests f luctuating asymmetry is relatively unimportant compared with direction al asymmetry.