Quantifying the strength and form of sexual selection on men's traits
Article InfoFig. 1
Linear (β) and quadratic (γ) relationships (statistics shown for statistically significant relationships) between men's traits, success under female choice and male contests, and mating success. Linear, quadratic and interaction terms for variables in each level to the left (e.g., men's traits) were entered into multiple regression models to predict variables at higher levels to the right (e.g., success under female choice). Biceps, chest, and shoulder circumference, and weight were standardized and summed to produce the composite variable, Girth. *p < .05, **p < .001, ***p < .0001.
Fig. 2
Correlational selection on eigenvectors m1 and m4 (see Table 2 ) under (A) female choice, (B) male contests, and (C) mating success.
Abstract
Although recent research has increasingly focused on human sexual selection, fundamental questions remain concerning the relative influence of individual traits on success in competition for mates and the mechanisms, form, and direction of these sexual selective pressures. Here, we explore sexual selection on men's traits by ascertaining men's dominance and attractiveness from male and female acquaintances. On a large American university campus, 63 men from two social fraternities provided anthropometric measurements, facial photographs, voice recordings, and reported mating success (number of sexual partners). These men also assessed each other's dominance, and 72 women from two socially affiliated sororities assessed the men's attractiveness. We measured facial masculinity from inter-landmark distances and vocal masculinity from acoustic parameters. We additionally obtained facial and vocal attractiveness and dominance ratings from unfamiliar observers. Results indicate that dominance and the traits associated with it predict men's mating success, but attractiveness and the traits associated with it do not. These findings point to the salience of contest competition on men's mating success in this population.
☆JH was funded by NERC and a University Royal Society Fellowship. LW was funded by an AIB grant awarded to DAP.
