Facial fluctuating asymmetry is not associated with childhood ill-health in a large British cohort study

Abstract

The idea that symmetry in facial traits is associated with attractiveness because it reliably indicates good physiological health, particularly to potential sexual partners, has generated an extensive literature on the evolution of human mate choice. However, large-scale tests of this hypothesis using direct or longitudinal assessments of physiological health are lacking. Here, we investigate relationships between facial fluctuating asymmetry (FA) and detailed individual health histories in a sample (n = 4732) derived from a large longitudinal study (Avon Longitudinal Study of Parents and Children) in South West England. Facial FA was assessed using geometric morphometric analysis of facial landmark configurations derived from three-dimensional facial scans taken at 15 years of age. Facial FA was not associated with longitudinal measures of childhood health. However, there was a very small negative association between facial FA and IQ that remained significant after correcting for a positive allometric relationship between FA and face size. Overall, this study does not support the idea that facial symmetry acts as a reliable cue to physiological health. Consequently, if preferences for facial symmetry do represent an evolved adaptation, then they probably function not to provide marginal fitness benefits by choosing between relatively healthy individuals on the basis of small differences in FA, but rather evolved to motivate avoidance of markers of substantial developmental disturbance and significant pathology.

Perception of health from facial cues

“…Contrary to the hypothesis that symmetry cues health, the largest study of facial asymmetry and health to date found no relationship between these variables [21]. Researchers used data from a British cohort study of 4732 individuals and found that facial symmetry at age 15 was unrelated to longitudinal measures of childhood health, including measures of the proportion of childhood years spent unwell, average number of illness symptoms per year, and total number of infections.…”

“…Ratings were averaged across participants for each face. [18][19][20][21][22][23][24][25][26][27][28][29] were taken using a camera in D65 lighting in a photographic booth painted with spectrally neutral grey and colour reference card (Gregtag Macbeth Mini ColorChecker Pantone). Clothing was covered with a grey-coloured board to prevent coloured reflection from clothing affecting facial illumination.…”

Analyzing Fluctuating Asymmetry with Geometric Morphometrics: Concepts, Methods, and Applications

“…To separate the two effects, it is possible to subtract the mean asymmetry to remove the effect of directional asymmetry before computing the Procrustes distance between the left and right shapes, so that the resulting distance indicates exclusively the magnitude of fluctuating asymmetry [11,41,239]. This measure of asymmetry, again, is available for both matching symmetry, where it is obtained from differences between the left and right sides [40,61,250,251], and for object symmetry, where it quantifies differences between original and reflected and relabeled configurations [86,94,102,105,134,148,252].…”

Developmental influences on fertility decisions by women: an evolutionary perspective

“…In a study of early stress and facial symmetry, lower socio-economic status during childhood, but not in midlife, was significantly associated with reduced facial symmetry at age 83 [157]. Recent attempts to examine developmental influences on attractiveness, focusing specifically on childhood health, have not been supported [158,159]. Consistent with this interpretation, in a study of Latvian women, facial attractiveness was not associated with immune responsiveness; however, it was associated with common correlates of stress.…”