Masculinity, skin color, and male facial attractiveness

Does Masculinity Matter? The Contribution of Masculine Face Shape to Male Attractiveness in Humans (PLoS ONE):

The proposal [. . .] that masculine men are immunocompetent and attractive – underpins a large literature on facial masculinity preferences. Recently, theoretical models have suggested that current condition may be a better index of mate value than past immunocompetence. This is particularly likely in populations where pathogenic fluctuation is fast relative to host life history. As life history is slow in humans, there is reason to expect that, among humans, condition-dependent traits might contribute more to attractiveness than relatively stable traits such as masculinity. [. . .]

The relationship between masculinity and attractiveness was assessed in two samples of male faces. Most previous research has assessed masculinity either with subjective ratings or with simple anatomical measures. Here, we used geometric morphometric techniques to assess facial masculinity, generating a morphological masculinity measure based on a discriminant function that correctly classified >96% faces as male or female. When assessed using this measure, there was no relationship between morphological masculinity and rated attractiveness. In contrast, skin colour – a fluctuating, condition-dependent cue – was a significant predictor of attractiveness.

The authors point out problems with attempts to assess the affect of masculinity on facial attractiveness that rely on human ratings of perceived masculinity or digital manipulation of photographs: (1) for rated masculinity, "subjective judgments of masculinity are based on factors other than just morphological masculinity"; (2) with morphing techniques, factors potentially more important than masculinity in determining real world attractiveness are not allowed to vary, and a preference for averageness might result in participants systematically preferring more or less masculine morphs even if women are completely indifferent to masculinity. As for the effects of skin color, in this sample:

The regression retained only skin yellowness as a predictor of attractiveness, and the effect of skin yellowness was positive and highly significant (F(1,71) = 10.806, Beta = .366, t = 3.287, p<.002). Skin lightness, redness and morphological masculinity did not significantly predict attractiveness (all p>.114, see Table 1).

Other studies have also found increased skin lightness and redness associated with perceived health and attractiveness. The association of yellowness with attractiveness "may be attributable to dietary carotenoid deposition in the skin. This suggests that carotenoids, which are involved in health signaling (Massaro et al. 2003; Saks et al. 2003) and sexual selection (Eley 1991; MacDougall and Montgomerie 2003; Massaro et al. 2003) in many species of birds and fish, may also affect the appearance of health in humans."