Women's intrasexual competitiveness, but not fertility, predicts greater competitive behavior toward attractive women across the menstrual cycle

Women compete for mates and social status, but little is known about the mechanisms that underlie these behaviors. Previous work suggests that mating competition should be most intense when women are fertile; thus, we hypothesized that women would exhibit more competitive behavior toward a high, rather than low, mating threat competitor during ovulation compared to other menstrual phases. Additionally, given that social support is crucial for women's access to resources and therefore offspring survival, we hypothesized that women would exhibit more competitive behavior toward a high, rather than low, social threat competitor following ovulation and possible conception. We tested 464 women recruited through social networking sites, psychology classes, and Prolific. Each rated their likelihood of exhibiting competitive behavior toward hypothetical mating and social competitors. Although women were more competitive toward the high, compared to low, mating and social threat competitors, there were no effects of cycle phase. Further, we found that intrasexual competitiveness, but not estimated hormones or other personality variables, predicted stronger competitive responses to the high mating threat competitor. We found no effects for social competitors. Together, these results suggest that in mating contexts, women's competition is dependent on individual tendency toward competition with other women, not fertility.