Abstract

Thousands of experimental studies in non-human species have documented the important role of testosterone, prenatally or neonatally, in sexual differentiation of the mammalian brain and subsequent behaviour. Early exposure to testosterone also influences gender-related human behaviours, contributing to behavioural differences between the sexes, and to individual differences within each sex. Other factors, including postnatal socialization and processes related to cognitive understanding of gender also are important for human gender development, and different types of influences combine in different ways to influence specific gender-related characteristics. Conclusions include: 1) Testosterone influences development of the human brain and behaviour; 2) Other factors also influence human gender development; 3) Neurobehavioural sexual differentiation is multidimensional, and different gender-related characteristics are subject to different combinations of influences.