Appearance of symmetry, beauty, and health in human faces

Abstract

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.

Three-Dimensional Facial Asymmetry in Attractive and Normal People from Childhood to Young Adulthood

“…The asymmetries in facial function (larger movements on the left than on the right side of the face) [10][11][12], as well as the most recent reports on the strict relationship between full and hemi-face attractiveness [36], are explained by asymmetries in human cerebral hemispheres, with resulting asymmetries in visual perception and interpretation of the surrounding world: The left side of the face receives a larger attention from the viewer [10,12,17,19,36,38]. Considering the importance of expressive features in the assessment of facial attractiveness [21], our asymmetric brain perception may explain the importance of mild facial asymmetries [36].…”

“…Persons with symmetric faces and bodies suggest to the observer that they possess good genes, a good general health, and are more resistant to diseases and parasites. Symmetric faces become "honest" markers of genotype and phenotype quality: Symmetry reflects the individual ability to maintain a stable development notwithstanding the environmental stress, thus being the result of natural selection [4,13,19,21,23,24,26,36,38].…”

“…Despite these theories, not all investigators concord about a strict relationships between facial symmetry and attractiveness from one side, and facial asymmetry and disease (or altered development) from the other side [1,12,18,21,27,36,38]. For instance, Peck et al [5] found that men and women considered attractive by the general public (beauty competition winners, professional models) had asymmetries in one or more craniofacial skeletal dimensions.…”

“…Similar protocols were followed by Peck et al [5] and by Ing et al [18] for two-dimensional hard-and softtissue craniofacial characteristics. This procedure contrasts with that followed in most studies about facial attractiveness, where the judgment was made on photographs (both original images, and composite or manipulated faces) of unselected persons [19,[21][22][23][24][25][26]33,36,38].…”

The Influence of Naturalness, Attractiveness and Intensity on Facial Emotion Recognition

“…These are rated, e.g., smarter, successful and full of moral fiber (O'Doherty, Winston, Chritchley, Perret, Burt, & Dolan, 2003;Dion, Berscheid, & Walster, 1972). It can be hypothesized that the preference for attractive partners goes along with evolutionary arisen concepts like survival of the fittest (Zaidel, Aarde, & Baig, 2005).…”