Men's, but not women's, sociosexual orientation predicts couples' perceptions of sexually dimorphic cues in own-sex faces

Previous research suggests that people's perceptions of own-sex individuals can change according to within-individual variation in their romantic partners' sexual strategies. For example, men are more likely to perceive other men's faces as looking particularly dominant during the fertile phase of their partner's menstrual cycle, when women tend to be more open to uncommitted sexual relationships. By contrast, little is known about how relatively stable between-individuals differences in partners' openness to uncommitted sexual relationships (i.e., their sociosexual orientation) predict perceptions of own-sex individuals. The revised Sociosexual Orientation Inventory (SOI-R) assesses individuals' openness to uncommitted sexual relationships and shows high test-retest reliability over long periods of time. Consequently, we tested whether the SOI-R scores of men and women in heterosexual romantic couples predicted their perceptions of own-sex faces displaying exaggerated sex-typical cues. Men's, but not women's, SOI-R was positively correlated with the extent to which both the man and woman within a couple ascribed high dominance and attractiveness to own-sex faces with exaggerated sex-typical cues. In other words, individuals in couples where the man reported being particularly open to uncommitted sexual relationships were more likely to ascribe dominance and attractiveness to own-sex individuals displaying a putative cue of good phenotypic condition. These findings suggest that both men's and women's perceptions of potential competitors for mates are sensitive to the male partner's sexual strategy. Such individual differences in perceptions may benefit men's ability to compete for extra-pair and/or replacement mates and benefit women's mate guarding behaviors.