Brain Sexual Differentiation and Gender Development

Human behavioral sex differences are currently understood to result from a combination of social, cultural, cognitive, and biological mechanisms. To understand how gender identity as the sexuality of the mind is formed is important for understanding psychosexual problems of children and to consider how to manage patients with disorders of sex development（DSD）, in which the development of gonads and genitals is atypical and it is difficult to determine the gender of boys and girls. There is consistent evidence that early testosterone exposure influences childhood gender role behavior, as well as gender identity and sexual orientation. In this review, we summarize the most relevant studies on the biological basis of sexual development. In particular, we focus on the impact of sex hormones and genetic background on development of sexual differentiation and gender identity, with introduction of our research using figure drawings by pediatric patients with congenital adrenal hyperplasia, which is also a DSD.