<p>There is strong agreement among adults both within and across cultures as to which faces are attractive (Langlois et al., 2000), and these perceptions can affect social interactions via the ‘beauty is good’ stereotype (Dion, Berscheid, & Walster, 1972). Adults perceive faces that are symmetrical to be more attractive than faces that are less symmetrical (Perrett et al., 1999), and faces that approximate the population average to be more attractive than most other faces (Langlois & Roggman, 1990). I examined the development of the influence of symmetry and averageness on children’s judgments of facial attractiveness in the faces of children and adults. In the work presented in chapters 2 and 3, I presented children and adults with pairs of faces that had been transformed to be more symmetrical and less symmetrical (chapter 2) or closer and farther from their group average (chapter 3). On each trial, participants selected which face was more attractive from the pair. I found that symmetry did not influence 5-year-olds’ judgments of attractiveness, but it did influence 9-year-olds’ judgments of attractiveness although to a lesser extent than those of adults. I additionally found that averageness strongly influenced 5-yearolds’ attractiveness judgments, and the strength of the preference increased from age 5 to 9, and from age 9 to adulthood. These findings are the first demonstrations that symmetry and averageness influence attractiveness judgments prior to adolescence, and that they influence attractiveness judgments in children’s faces. To assess whether natural differences in face experience can affect how strongly averageness is preferred in different face categories, I tested children attending single-sex schools and expected averageness to influence attractiveness judgments more strongly in same-sex than opposite-sex faces of their own age (chapter 4). I did not find that pattern of results. Averageness might influence attractiveness judgments regardless of the age and sex of face because a minimum level of face experience could be adequate for attractiveness judgments based on a prototype and/or because of similarities among averages of different ages and sexes. Together, the findings of this thesis demonstrate that children assess facial attractiveness based on some of the same dimensions as do adults, but that children are more tolerant of deviations from averageness and symmetry. Developmental changes might reflect the refinement of a face prototype as experience with faces increase, increased visual sensitivity as the visual system develops, and/or increased salience of cues for mate choice after puberty.</p> / Doctor of Science (PhD)

Dans ce travail de thèse, nous avons confronté l’explication du fitness model à celle du stéréotype beautiful is good, afin de mieux saisir l’influence de l’attractivité faciale d’un homme sur les préférences d’une femme. Selon le fitness model, une femme interprèterait l’attractivité faciale d’un homme comme l’indice de sa bonne santé (bonne condition génétique), profitable à la survie et au succès reproducteur de la progéniture. Mais selon des travaux en lien avec l’aisance cognitive (prototype, stéréotype beautiful is good), les traits attractifs et l’attention qu’une femme manifeste pour l’attractivité faciale d’un homme n’auraient pas de valeur reproductive, et s’expliqueraient plutôt en termes de facilité de traitement et d’économie cognitive, qui génèrent des réactions positives. Nous avons eu recours à un logiciel de ‘morphing’ afin de créer des visages artificiels d’hommes dont le genre, la correspondance à une moyenne et la symétrie variaient, et les avons fait évaluer par des femmes françaises et marocaines sur différents points : attractivité faciale, santé, revenus, rencontre, partenaire sur le long terme. Les résultats mettent en évidence que l’influence de l’attractivité faciale sur les préférences des femmes n’aurait pas seulement une valeur reproductive, et que l’économie cognitive permise par le recours au stéréotype beautiful is good expliquerait aussi les préférences. / In this work of thesis, we compared the fitness model explanation with the beautiful is good stereotype point of view to better evaluate the influence of men’s facial attractiveness on women preferences. According to the fitness model, a woman would interpret men’s facial attractiveness as an indicator of their good health (good genetic condition), profitable for the offspring’s survival and reproductive success. But according to studies in the field of cognitive ease (prototype, beautiful is good stereotype), the attractive facial features and the attention that a woman pay to men’s facial attractiveness is explained in terms of easy processing and cognitive economy, which generate positive reactions and would have no reproductive value. We used a software of morphing to create artificial men’s faces among which the masculine vs feminine, the averageness and the symmetry were manipulated. After, we submitted these faces to the evaluation of french and moroccan women on several aspects : facial attractiveness, health, income, meeting, long-term mate. The results suggest that facial attractiveness’s influence on women’s preferences would not only have a reproductive value, and that the cognitive economy allowed by the beautiful is good stereotype would also explain the preferences.