Mate Competition between the Sexes

Abstract

Abstract Darwinian sexual selection has been the dominant framework for understanding mate competition, which usually involves intrasexual competition for opposite-sex partners. This expected dynamic can become more complicated in any species that shows an appreciable rate of bisexual behavior. Specifically, intersexual mate competition is possible any time opposite-sex individuals engage in romantic/sexual competition over the same target. We review historical and ethnographic evidence that intersexual mate competition occurs among humans. Going further, we describe data from two different non-Western cultures—Samoa and the Istmo Zapotec (Oaxaca, Mexico). These data show that competitions to acquire and maintain sexual relationships with men occur between women and feminine same-sex attracted males. This intersexual mate competition most commonly involved feminine males attempting to mate-poach partnered men from their relationships with women. Using participant stories to complement mixed-methods data, we illustrate how these competitions typically involved feminine males attempting to entice the target man, whereas women engaged in mate-guarding and emotionally punitive behaviors. Although intersexual mate competition is unlikely to be found in most species, or across all human cultures, our data show that intersexual mate competition can ensue when males and females prefer the same sexual partners, who themselves behave in a bisexual manner.