Averageness

Abstract: What makes a face attractive and why do we have the preferences we do? Emergence of preferences early in development and cross-cultural agreement on attractiveness challenge a long-held view that our preferences reflect arbitrary standards of beauty set by cultures. Averageness, symmetry, and sexual dimorphism are good candidates for biologically based standards of beauty. A critical review and meta-analyses indicate that all three are attractive in both male and female faces and across cultures. Theorists have proposed that face preferences may be adaptations for mate choice because attractive traits signal important aspects of mate quality, such as health. Others have argued that they may simply be by-products of the way brains process information. Although often presented as alternatives, I argue that both kinds of selection pressures may have shaped our perceptions of facial beauty.

Abstract: Scientists and philosophers have searched for centuries for a parsimonious answer to the question of what constitutes beauty. We approached this problem from both an evolutionary and information-processing rationale and predicted that faces representing the average value of the population would be consistently judged as attractive. To evaluate this hypothesis, we digitized samples of male and female faces, mathematically averaged them, and had adults judge the attractiveness of both the individual faces and the computer-generated composite images. Both male (three samples) and female (three samples) composite faces were judged as more attractive than almost all the individual faces comprising the composites. A strong linear trend also revealed that the composite faces became more attractive as more faces were entered. These data showing that attractive faces are only average are consistent with evolutionary pressures that favor characteristics close to the mean of the population and with cognitive process...

Abstract: Testosterone-dependent secondary sexual characteristics in males may signal immunological competence1 and are sexually selected for in several species2,3. In humans, oestrogen-dependent characteristics of the female body correlate with health and reproductive fitness and are found attractive4,5,6. Enhancing the sexual dimorphism of human faces should raise attractiveness by enhancing sex-hormone-related cues to youth and fertility in females5,7,8,9,10,11, and to dominance and immunocompetence in males5,12,13. Here we report the results of asking subjects to choose the most attractive faces from continua that enhanced or diminished differences between the average shape of female and male faces. As predicted, subjects preferred feminized to average shapes of a female face. This preference applied across UK and Japanese populations but was stronger for within-population judgements, which indicates that attractiveness cues are learned. Subjects preferred feminized to average or masculinized shapes of a male face. Enhancing masculine facial characteristics increased both perceived dominance and negative attributions (for example, coldness or dishonesty) relevant to relationships and paternal investment. These results indicate a selection pressure that limits sexual dimorphism and encourages neoteny in humans.

Abstract: We hypothesized from the parasite theory of sexual selection that men (Homo sapiens) would prefer averageness and symmetry in women's faces, that women would prefer averageness and symmetry in men's faces, and that women would prefer largeness (not averageness) of the secondary sexual traits of men's faces. We generated computer images of men's and women's faces and of composites of the faces of each sex, and then had men and women rate opposite-sex faces for 4 variables (attractive, dominant, sexy, and healthy). Symmetry, averageness, and the sizes of facial features were measured on the computerized faces. The hypotheses were supported, with the exception of the hypothesized effects of averageness of female and male faces on attractiveness ratings. This is the first study to show that facial symmetry has a positive influence on facial attractiveness ratings. Although adult facial attractiveness ratings are replicable, even cross-culturally (see reviews and discussions in Jones & Hill, 1993, and Langlois & Roggman, 1990), there has been considerable controversy around attempts to identify in research the facial features that actually cause faces to be judged attractive or unattractive. As discussed by Langlois and Roggman, studies of individual facial features (e.g., nose size) often have yielded inconsistent results between studies. Faces created by combining individual faces into composites have been shown to be more attractive than the individual faces, which is felt to be a preference for average facial features (Langlois & Roggman, 1990; Symons, 1979). Averageness effaces can be calculated metrically or constructed photogrammetrically. Gallon (1879) constructed composites of individual pictures with the photographic method of simply projecting them one over the other on a negative. According to Gallon, this method "enables us to obtain with mechanical precision a generalized picture; one that represents no man in particular, but portrays an imaginary figure possessing the average features of any given group of man" (1879, p. 341). Indeed, Treu (1914) had the impression that these composites are "singularly beautiful" (p. 441). However, as Alley and Cunningham (1991; see also Benson & Perrett, 1991) pointed out, composites are also more symmetrical and rather free of