Biological bases of beauty revisited: The effect of symmetry, averageness, and sexual dimorphism on female facial attractiveness

Abstract

The theoretical factors influencing human female facial attractiveness – symmetry, averageness,and sexual dimorphism – have been extensively studied. However, through improved methodologies, recent studies have called into question their links with life history and evolutionary utility. The current study uses a range of statistical and methodological approaches to quantify how important these factors actually are in perceiving attractiveness, through the use of novel analyses and by addressing methodological weaknesses inherent in the literature. Study One examines how manipulations of symmetry, averageness, femininity, and masculinity affect attractiveness using a two-alternative forced choice task, revealing that increased masculinity is unattractive, but increased femininity is not, and large effects observed for averageness. Study Two utilises a naturalistic ratings paradigm, finding similar effects of averageness and masculinity, but no effects of femininity and symmetry on attractiveness. Study Three applies a random forest machine learning algorithm and geometric measurements of the factors from faces to predict perceived attractiveness, finding that averageness and dimorphism are useful features capable of relatively accurate predictions. However, the factors do not explain as much variance in attractiveness as the wider literature suggests. Implications for future research on attractiveness are discussed.

Women’s Preferences for Sexual Dimorphism in Faces: Data from a Sample of Arab Women

“…However, they differ from those of studies of US and Jamaican women's face preferences, which reported that women tended to prefer masculinized versions of men's faces over feminized versions (e.g., Johnston et al 2001;Penton-Voak et al 2004;Rennels et al 2008). Although some work has recently demonstrated that women's face preferences can differ according to the type of paradigm used to assess preferences (Jones and Jaeger 2019), this effect of testing paradigm is unlikely to explain this difference in preferences across studies: all of the studies described above employed similar forced-choice paradigms.…”

Sexual orientation predicts men’s preferences for sexually dimorphic face-shape characteristics: a replication study.

“…We used this paradigm in our study because it was the same as that used in the study by Glassenberg et al [8] that we were attempting to (and successfully did) replicate. However, some recent research suggests that forced-choice paradigms can produce qualitatively different patterns of results that other methods for assessing preferences for sexually dimorphism face-shape characteristics [18]. Establishing the extent to which the effects of sexual orientation on face preferences that we observed in the current study and that were also observed by Glassenberg et al [8] generalize to other methods for assessing face preferences would be an important direction for future research.…”

No evidence that partnered and unpartnered gay men differ in their preferences for male facial masculinity

“…Some work suggests that findings for forced choice preferences (the type of preferences we assessed in the current study) do not necessarily generalize to studies using rating paradigms [19]. Since Valentová et al [10] used a rating paradigm, this type of paradigm-contingent difference might explain why we did not replicate the effect of partnership status that they reported.…”