Strong personalities: Investigating the relationships between grip strength, self-perceived formidability, and Big Five personality traits

Individuals vary in physical size, strength, and overall physical formidability, and this variation has potential consequences for the relative costs and benefits of certain types of social interactions. For example, dispositional vigilance towards potential ecological or social threats may be more beneficial for less formidable (relative to more formidable) individuals. However, previous research has only begun to elucidate the relationship between formidability and broad personality traits. In the current research we explored the relationships between hand grip strength and Big Five personality traits, and found relationships that were partly - but not entirely - consistent with previous research. Across two samples of American undergraduates (N > 500), we found negative correlations between grip strength and neuroticism in both men and women, but no correlation between grip strength and other Big Five traits. In Study 2, we also extended previous research by examining self-reported perceived formidability. Perceived formidability correlated negatively with neuroticism and positively with extraversion in both sexes. Importantly, perceived formidability also mediated the relationship between grip strength and neuroticism. Finally, exploratory analyses revealed that differences in grip strength also fully accounted for sex differences in neuroticism.