Physical Strength Partly Explains Sex Differences in Trait Anxiety in Young Americans

Among the most consistent sex differences to emerge from personality research is that women score higher than men on the Big Five personality trait Neuroticism. However, there are few functionally coherent explanations for this sex difference. The current studies tested whether this sex difference is due, in part, to variation in physical capital. Two preregistered studies (total N = 878 U.S. students) found that sex differences in the anxiety facet of Neuroticism were mediated by variation in physical strength and self-perceived formidability. Study 1 (N = 374) did not find a predicted mediation effect for overall Neuroticism but found a mediation effect for anxiety (the facet of Neuroticism most strongly associated with grip strength). Study 2 (N = 504) predicted and replicated this mediation effect. Further, sex differences in anxiety were serially mediated by grip strength and self-perceived formidability. These findings add to a nascent literature suggesting that differences in physical attributes may partially explain sex differences in personality.