Genetic and environmental influences on verbal and nonverbal measures of the Big Five

This study reports the first behavioral genetic investigation of a nonverbal measure of the Big Five and its relationship with a traditional verbal measure. Participants (N = 592 adult twins) completed the Five-Factor Nonverbal Personality Questionnaire and the Revised NEO Personality Inventory. Monozygotic twins were more alike on all domains of the Big Five as assessed by both sets of scales than were dizygotic twins, and univariate behavioral genetic model-fitting showed that individual differences in both the nonverbal and verbally assessed traits were entirely attributable to additive genetic and non-shared environmental factors. Positive phenotypic correlations were found between the same personality factors assessed by the verbal and nonverbal measures and these correlations were themselves entirely attributable to correlated genetic and correlated non-shared environmental factors. The results provide evidence for the validity of the newly-devised FF-NPQ.