1Anthropology, University of Washington, 2Anthropology, University of Utah, 3Anthropology, University of Cincinnati, 4Anthropology, Texas A&M University, 5Psychology, University of Basel, 6Anthropology, The Pennsylvania State University
April 14, 2018 , Zilker 1/2/3
Men’s secondary sex traits predict attractiveness, dominance, and mating success. Although intrasexual rivalry and intersexual choice may have differed in relative strength across men’s traits ancestrally, recent research suggests that contest competition may generally have influenced the male phenotype more than have female preferences. However, few available data link men’s putative sexually selected traits to success under mate choice and contests, and to mating and reproductive success, in natural fertility populations. We therefore explored the relative degrees to which these mechanisms of sexual selection mediate relationships between male traits and fitness in a small-scale Central American society with minimal use of contraception. In 51 men aged 20-40 years, we measured sexually dimorphic traits of the face, voice, and body, as well as success in male contests, female choice, mating, and reproduction. Multiple regression analyses revealed that (1) men’s secondary sex traits predicted dominance, and not attractiveness, but that (2) attractiveness, and not dominance, predicted fitness outcomes with age controlled. This is attributable to greater quantity, not quality, of female mates. We discuss implications of these results concerning the relative importance of intrasexual and intersexual selection in men.