Abstract

We investigate whether prenatal testosterone is related to educational performance. Twin testosterone transfers are believed to increase exposure to prenatal testosterone for those with a male co-twin. Given that the sex of the co-twin is determined randomly, this provides exogenous variation in prenatal testosterone which can be used to study a potential biological determinant of educational performance. It might thereby provide a potential explanation for the gender gap in mathematics. Administrative data on a large sample of Dutch twins is used. No increased performance is found for boys and girls with a male co-twin. If anything, the effects for girls would be negative. This changes when restricting the analysis to later years, in which gender differences are less pronounced. Having a male co-twin significantly increases performance in all domains for men. Whereas females with a male co-twin perform worse in math