Second-to-fourth digit ratio related to Verbal and Numerical Intelligence and the Big Five

Androgens influence individual differences in a predictable way: they “masculinise” people. The ratio of index finger length to ring finger length (2D:4D) is an index of prenatal androgen exposure. We related 2D:4D to Verbal Intelligence, Numerical Intelligence and the Big Five personality dimensions in a Dutch sample of 44 men and 37 women. We found a relation between right-hand 2D:4D and Verbal and Numerical Intelligence as well as Agreeableness (R2’s around .22), in a typical masculine pattern (low 2D:4D, low verbal intelligence, high numerical intelligence, and low agreeableness). We conclude 2D:4D is a valuable tool in the study of the determinants of individual differences.