Abstract
In a context of mate choice, preferences are psychological mechanisms allowing individuals to choose a partner who can enhance their reproductive success. As a man's number of children greatly depends on the fertility of his mate(s), the ability to detect and prefer women with a high fertility has been selected. Moreover, as a woman's fertility is linked to various physical features, female attractiveness is largely physical. An experimental approach has been used to identify the physical traits influencing women's attractiveness, as well as the fertility characteristics of which they are the cues. In addition to well known cues of current fertility (i.e. a woman's ability to conceive a child at that given time), our results show that men are also sensitive to cues for residual fertility (i.e. the potential number of children a woman could have in the future), which is partially determined by age at menopause. Male means of detecting these features have been analysed too, highlighting the crucial role of the peripheral vision when judging the attractiveness of a woman's body. Furthermore, the issue of whether these attractiveness standards are universal has been addressed. Our studies show that men's preferences vary through time (the ideal body shape, determined by the waist-to-hip ratio, has changed since the 15th century), geographically (preferences concerning the residual fertility differ between France and Indonesia), and individually (a preference for homogamy has been found within facial features). Thus, our results disprove the notion of a single, universal and biologically fixed idea of beauty. But these variations of preferences are not arbitrary, and can be explained by evolutionary stakes and trade-offs, linked to environmental, cultural and individual conditions.