Psychobiology of facial attractiveness.

The last decade has witnessed an upsurge of interest in the research on facial attractiveness. The development of computer graphics has allowed to objectively investigate the conserved features of attractive faces. Averageness, symmetry and sex-specific traits have been associated with attractiveness. The effect of averageness is exemplified by blending a set of real faces into a chimeric face. This composite is more attractive than most of the faces used to create it. Beautiful faces are not simply average faces, however. If the female-specific features of a female composite face are enhanced, the resulting face is perceived as more attractive than the composite. In particular, smaller than average chin, smaller than average nose and higher than average forehead, all are traits associated with female's attractiveness. These traits have been interpreted as signs of high estrogen/testosterone ratio and therefore cues of high fertility. However, these same traits are also a species-specific characteristic of Homo sapiens that differentiates it from other hominid species. Preference for caricature of human features could represent a relic of species recognition mechanisms. Female preferences for male faces proved to be more variable than male preferences for female faces. Different facial traits are preferred in the choice of short-term and long-term partners. Preference for short term depend on the hormonal status and changes across the menstrual cycle and is influenced by contraceptive hormonal treatment. Psychological factors are also important sources of variance: female preferences correlate with self-perceived attractiveness, status in a relationship and degree of gender-conformity.