A new UK study suggests sexual orientation and “gender conformity” in women are both genetic traits.
Researchers from Queen Mary, University of London, based their study on the observation of consistent differences in the psychological characteristics of boys and girls. For example, boys engage in more “rough and tumble” play than girls do.
Prior studies have shown that children who become gay or lesbian adults differ in such traits from those who become heterosexual — so-called gender nonconformity.
Research following these children to adulthood shows that between 50 to 80 per cent of gender nonconforming boys become gay, and about one-third of such girls become lesbian.
In the current study, psychologists Drs. Andrea Burri and Qazi Rahman report that a shared set of genes and shared set of random environmental factors is partially responsible both for gender nonconformity and female sexual orientation.
The study is published in PLoS One.
Researchers followed a group of 4,000 British women who were one of a pair of twins. They were asked questions about their sexual attractions and behavior, and a series of follow up questions about their gender nonconformity.
Results were similar to previous research as the team found modest genetic influences on sexual orientation (25 per cent) and childhood gender nonconformity (31 per cent).
Said Rahman: “We found that there is a connection between these mental traits and how sexual orientation develops. One idea is that 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.”
“We think environmental factors and genetics drive other mechanisms, like exposure to sex hormones in the womb, to shape differences in gender nonconformity and sexuality simultaneously.”
Rahman is mindful that the results may carry the risk of stereotyping, and said: “Stereotypes like ‘sissy’ or ‘mannish’ have not been helpful in promoting respect for gay people, and those who don’t match those stereotypes may find it hard to accept they are gay or lesbian.”
The researchers believe the findings are important for improving the mental health of sexual minorities. “We know that gay people who are strongly gender nonconforming report more anxiety and depression symptoms.,” Rahman said.
“Poor mental health in gay populations is partly due to societal stigma and victimization. Our results suggest that being gender-nonconforming and lesbian comes from ‘within’; there is little you can do about it. So gender nonconformity does not cause mental health problems, but it may trigger negative reactions from other people (like parents and peers) leading to mental health problems.”
Source: Queen Mary, University of London