Explained: The biggest ever study on same-sex sexuality is out. Why has it triggered concern?https://indianexpress.com/article/explained/explained-the-biggest-ever-study-on-same-sex-sexuality-is-out-why-has-it-triggered-concern-5951323/

Explained: The biggest ever study on same-sex sexuality is out. Why has it triggered concern?

The study was funded by several agencies, led by the US National Institutes of Health, the world’s largest biomedical research agency.

Explained: The biggest ever study on same-sex sexuality is out. Why has it triggered concern?
Over four years from 2006 to 2010, the subjects answered a range of questions on health and behaviour. (Express file photo)

The largest study of its kind ever done has suggested that genes have perhaps one-third of the role in determining whether a person is gay or straight, and the rest of the role is played by social and environmental factors.

Even to the extent that genes play a role, it is not one particular gene that is responsible — rather, a large number of genes have a series of small impacts. In effect then, it is not possible to predict, on the basis of genetics, the sexuality of any individual.

“I hope that the science can be used to educate people a little bit more about how natural and normal same-sex behaviour is,” a report in The New York Times quoted Benjamin Neale, one of the lead researchers, as saying. “It’s written into our genes and it’s part of our environment. This is part of our species and it’s part of who we are.”

What is the study?

The research looked at genetic data of well over 4 lakh men and women from a British database called the UK Biobank. Over four years from 2006 to 2010, the subjects, who were then aged 40-69, answered a range of questions on health and behaviour.

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In addition, the study analysed data from nearly 70,000 clients of a genetic testing service called 23andMe. The average age of these individuals was 51, and they were mostly from the United States. This group answered questions about sexual orientation.

The responses of all subjects of the study, who were exclusively of white European descent, were studied with the primary focus on the question: “Have you ever had sex with a partner of your own sex?”

The study was funded by several agencies, led by the US National Institutes of Health, the world’s largest biomedical research agency.

Immediate concerns

The study, which was published in the journal Science on Thursday, triggered a wave of concern and criticism even before its results had been fully known, mainly within a group of scientists who identify themselves as part of the LGBTQ community. At the heart of the concern lay the fact that human sexuality is complicated, and the research findings could be misconstrued and misused.

There were those who worried that evidence that genes played a role in determining whether a person demonstrates same-sex behaviour, would trigger calls by anti-gay groups to use gene-editing to “fix” or “cure” gay people. These groups, the scientists worried, would try to hijack science to the end of reaffirming biases and prejudice against gay people.

And equally, there were others who articulated fears that evidence from the research that genes play only a part of the role in determining same-sex behaviour, would provide ammunition to people who claim that being gay is a “choice”, and that these people will then try to enforce tactics such as “therapy”, again with the intention to “cure”.

“I deeply disagree about publishing this,” The New York Times report quoted geneticist Steven Reilly as saying. “It seems like something that could easily be misconstrued… In a world without any discrimination, understanding human behaviour is a noble goal, but we don’t live in that world.”

What the study found

The research suggests that all genetic effects together add up to about 32% of the possibility of whether an individual will have a same-sex sexual partner. Single-letter differences in DNA sequences account for 8%-25% of such sexual behaviour; the rest likely involve genetic effects that could not be measured.

Five genetic variants in the full genome were identified by the researchers as being involved. These five variants make up under 1% of the genetic influences, they said.

The research showed some evidence of genetic correlations between same-sex sexual behaviour and mental health issues such as major depressive disorder or schizophrenia, and with social habits such as risk-taking and loneliness.

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However, the researchers have emphasised that the study does not suggest that same-sex sexual behaviour either causes or is caused by these conditions. “We are particularly worried that people will misrepresent our findings about mental health,” one of the lead researchers has been quoted as saying.