Symmetry and human facial attractiveness

Journal of Comparative Psychology; …, 1994

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.

Proceedings of the Royal Society B: Biological Sciences, 1999

Cues of phenotypic condition should be among those used by women in their choice of mates. One marker of better phenotypic condition is thought to be symmetrical bilateral body and facial features. However, it is not clear whether women use symmetry as the primary cue in assessing the phenotypic quality of potential mates or whether symmetry is correlated with other facial markers a¡ecting physical attractiveness. Using photographs of men's faces, for which facial symmetry had been measured, we found a relationship between women's attractiveness ratings of these faces and symmetry, but the subjects could not rate facial symmetry accurately. Moreover, the relationship between facial attractiveness and symmetry was still observed, even when symmetry cues were removed by presenting only the left or right half of faces. These results suggest that attractive features other than symmetry can be used to assess phenotypic condition. We identi¢ed one such cue, facial masculinity (cheek-bone prominence and a relatively longer lower face), which was related to both symmetry and full-and half-face attractiveness.

Psychonomic Bulletin & Review, 1998

Evolutionary, as well as cultural, pressures may contribute to our perceptions of facial attractiveness. Biologists predict that facial symmetry should be attractive, because it may signal mate quality. We tested the prediction that facial symmetry is attractive by manipulating the symmetry of individual faces and observing the effect on attractiveness, and by examining whether natural variations in symmetry (between faces) correlated with perceived attractiveness. Attractiveness increased when we increased symmetry, and decreased when we reduced symmetry, in individual faces (Experiment 1), and natural variations in symmetry correlated significantly with attractiveness (Experiments 1 and lA). Perfectly symmetric versions, made by blending the normal and mirror images of each face, were preferred to less symmetric versions of the same faces (even when those versions were also blends) (Experiments 1 and 2). Similar results were found when subjects judged the faces on appeal as a potential life partner, suggesting that facial symmetry may affect human mate choice. We conclude that facial symmetry is attractive and discuss the possibility that this preference for symmetry may be biologically based. The question of what makes a face attractive, and whether our preferences come from culture or biology, has fascinated scholars for centuries. Variation in the ideals of beauty across societies and historical periods suggests that standards of beauty are set by cultural convention. Recent evidence challenges this view, however, with infants as young as 2 months of age preferring to look at faces that adults find attractive (Langlois et aI., 1987), and people from different cultures showing considerable agreement about which faces are attractive (Cunningham, Roberts, Wu, Barbee, & Omen, 1995; Jones & Hill, 1993; see Langlois & Roggman, 1990, for a review). These findings raise the possibility that some standards of beauty may be set by nature rather than culture. Consistent with this view, specific preferences have been identified that appear to be part of our biological rather than our social heritage (

2001

Facial symmetry has been proposed as a marker of developmental stability that may be important in human mate choice. Several studies have demonstrated positive relationships between facial symmetry and attractiveness. It was recently proposed that symmetry is not a primary cue to facial attractiveness, as symmetrical faces remain attractive even when presented as half faces (with no cues to symmetry). Facial sexual dimorphisms (`masculinity') have been suggested as a possible cue that may covary with symmetry in men following data on trait size/symmetry relationships in other species. Here, we use real and computer graphic male faces in order to demonstrate that (i) symmetric faces are more attractive, but not reliably more masculine than less symmetric faces and (ii) that symmetric faces possess characteristics that are attractive independent of symmetry, but that these characteristics remain at present unde¢ned.

The ''good genes'' explanation of attractiveness posits that mate preferences favour healthy individuals due to direct and indirect benefits associated with the selection of a healthy mate. Consequently, attractiveness judgements are likely to reflect judgements of apparent health. One physical characteristic that may inform health judgements is fluctuating asymmetry as it may act as a visual marker for genetic quality and developmental stability. Consistent with these suggestions, a number of studies have found relationships between facial symmetry and facial attractiveness. In Study 1, the interplay between facial symmetry, attractiveness, and judgements of apparent health was explored within a partial correlation design. Findings suggest that the attractiveness -symmetry relationship is mediated by a link between judgements of apparent health and facial symmetry. In Study 2, an opposite-sex bias in sensitivity to facial symmetry was observed when judging health. Thus, perceptual analysis of symmetry may be an adaptation facilitating discrimination between potential mates on the basis of apparent health. The findings of both studies are consistent with a ''good genes'' explanation of the attractiveness -symmetry relationship and problematic for the claim that symmetry is attractive as a by-product of the ease with which the visual recognition system processes symmetric stimuli. D

2004

Studies have shown that male faces high in symmetry are judged more attractive than faces low in symmetry even in images where visual cues to facial symmetry are reduced. These findings suggest that there are correlates of facial symmetry that influence male facial attractiveness independently of symmetry itself. Apparent healthiness of facial skin is one factor that may influence male facial attractiveness and covary with facial symmetry. Here, using real and composite male faces, we found that males with symmetric faces were perceived as having healthier facial skin than males with relatively asymmetric faces (Study 1), and that facial colour and texture cues were sufficient to maintain an attractiveness -symmetry relationship when the influence of facial shape was minimised (Study 2). These findings suggest that colour and texture cues contribute to the relationship between attractiveness and symmetry in real faces. D 2004 Elsevier Inc. All rights reserved.

Brain and Cognition, 2005

Symmetry is an important concept in biology, being related to mate selection strategies, health, and survival of species. In human faces, the relevance of left-right symmetry to attractiveness and health is not well understood. We compared the appearance of facial attractiveness, health, and symmetry in three separate experiments. Participants inspected front views of faces on the computer screen and judged them on a 5-point scale according to their attractiveness in Experiment 1, health in Experiment 2, and symmetry in Experiment 3. We found that symmetry and attractiveness were not strongly related in faces of women or men while health and symmetry were related. There was a significant difference between attractiveness and symmetry judgments but not between health and symmetry judgments. Moreover, there was a significant difference between attractiveness and health. Facial symmetry may be critical for the appearance of health but it does not seem to be critical for the appearance of attractiveness, not surprisingly perhaps because human faces together with the human brain have been shaped by adaptive evolution to be naturally asymmetrical.

Acta psychologica, 2004

Behavioral Ecology, 2008

Symmetry and masculinity in human faces have been proposed to be cues to the quality of the owner. Accordingly, symmetry is generally found attractive in male and female faces, and femininity is attractive in female faces. Women's preferences for male facial masculinity vary in ways that may maximize genetic benefits to women's offspring. Here we examine same-and opposite-sex preferences for both traits (Study 1) and intercorrelations between preferences for symmetry and sexual dimorphism in faces (Study 1 and Study 2) using computer-manipulated faces. For symmetry, we found that male and female judges preferred symmetric faces more when judging faces of the opposite-sex than when judging same-sex faces. A similar pattern was seen for sexual dimorphism (i.e., women preferred more masculine male faces than men did), but women also showed stronger preferences for femininity in female faces than men reported. This suggests that women are more concerned with female femininity than are men. We also found that in women, preferences for symmetry were positively correlated with preferences for masculinity in male faces and that in men preferences for symmetry were positively correlated with preferences for femininity in female faces. These latter findings suggest that symmetry and sexual dimorphism advertise a common quality in faces or that preferences for these facial cues are dependent on a common quality in the judges. Collectively, our findings support the view that preferences for symmetry and sexual dimorphism are related to mechanisms involved in sexual selection and mate choice rather than functionless by-products of other perceptual mechanisms.

… of the Royal …, 2001

Exaggerated sexual dimorphism and symmetry in human faces have both been linked to potential`goodgene' bene¢ts and have also been found to in£uence the attractiveness of male faces. The current study explores how female self-rated attractiveness in£uences male face preference in females using faces manipulated with computer graphics. The study demonstrates that there is a relatively increased preference for masculinity and an increased preference for symmetry for women who regard themselves as attractive. This ¢nding may re£ect a condition-dependent mating strategy analogous to behaviours found in other species. The absence of a preference for proposed markers of good genes may be adaptive in women of low mate value to avoid the costs of decreased parental investment from the owners of such characteristics.