title: Facial averageness and genetic quality: Testing heritability, genetic correlation with attractiveness, and the paternal age effect.
abstract: Popular theory suggests that facial averageness is preferred in a partner for genetic benefits to offspring. However, whether facial averageness is associated with genetic quality is yet to be established. Here, we computed an objective measure of facial averageness for a large sample (N= 1,823) of identical and nonidentical twins and their siblings to test two predictions from the theory that facial averageness reflects genetic quality. First, we use biometrical modelling to estimate the heritability of facial averageness, which is necessary if it reflects genetic quality. We also test for a genetic association between facial averageness and facial attractiveness. Second, we assess whether paternal age at conception (a proxy of mutation load) is associated with facial averageness and facial attractiveness. Our findings are mixed with respect to our hypotheses. While we found that facial averageness does have a genetic component, and a significant phenotypic correlation exists between facial averageness and attractiveness, we did not find a genetic correlation between facial averageness and attractiveness (therefore, we cannot say that the genes that affect facial averageness also affect facial attractiveness) and paternal age at conception was not negatively associated with facial averageness. These findings support some of the previously untested assumptions of the 'genetic benefits' account of facial averageness, but cast doubt on others.
authors: School of Psychology, University of Queensland, Brisbane, Queensland, Australia.
authors: Anthony J
authors: AJ
authors: Lee
authors: Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado, United States of America; Institute for Behavioral Genetics, University of Colorado Boulder, Boulder, Colorado, United States of America.
authors: Dorian G
authors: DG
authors: Mitchem
authors: QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.
authors: Margaret J
authors: MJ
authors: Wright
authors: QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.
authors: Nicholas G
authors: NG
authors: Martin
authors: Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado, United States of America; Institute for Behavioral Genetics, University of Colorado Boulder, Boulder, Colorado, United States of America.
authors: Matthew C
authors: MC
authors: Keller
authors: School of Psychology, University of Queensland, Brisbane, Queensland, Australia; QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.
authors: Brendan P
authors: BP
authors: Zietsch
keywords: Mate preference; developmental stability; good genes; mutation load; physical attractiveness; twins