Study: Sexuality in Lesbians Is Based on Genes

Gay men are more likely than lesbians to show gender-nonconforming traits during childhood, according to a new study by Queen Mary University in London.

Research following children to adulthood shows that 50%-80% of gender-nonconforming boys grow up to be gay. Meanwhile, only about one-third of nonconforming girls become lesbians.

Psychologists Andrea Burri and Qazi Rahman report that genes may be partially responsible for nonconforming traits as well as sexual orientation.

Burri and Rahman followed a group of 4,000 women who were part of pairs of twins. After asking about their sexual attractions, behavior, and gender nonconformity, the team found genetic influences on orientation (25%) and childhood gender nonconformity (31%).

Ultimately, there is a connection between mental traits and sexual orientation development.

"There is an association between these psychological traits and sexual orientation because they all develop under common biological drivers, like the development of brain regions under the influence of genes and sex hormones," explained Rahman.