A behavioural genetic study of mental toughness and personality

The present study is the first behavioural genetic (BG) investigation of mental toughness, as measured by the 48-item mental toughness (MT48) questionnaire, and the first BG investigation of relationships between mental toughness and the Big-5 factors of personality. Participants were 219 pairs of adult monozygotic and dizygotic twins from across North America. Twin study methodology was used to determine the extent to which genes and/or environmental factors contributed to individual differences in mental toughness and also to determine the genetic and/or environmental basis of any relationship between mental toughness and personality. Univariate BG analyses revealed that individual differences in mental toughness (as well as in personality) were largely attributable to genetic and nonshared environmental factors. Bivariate BG analyses revealed that phenotypic correlations between mental toughness and personality were largely attributable to common genetic and common nonshared environmental factors.