Science Magazine published a massive study on Thursday dispelling the idea that same-gender sexual behavior is caused by a particular gene, but "for the first time we can say without a reasonable doubt that some genes do influence the propensity to have same-sex partners."
[iframe https://giphy.com/embed/ElErGrTbomQ6c allowfullscreen="" class=^{{"giphy-embed"}}^ frameborder="0" height="360" width="480"]
The study looked for variations in the genes of 470,000 people from around the globe, many gathered voluntarily from users of DNA testing company 23 and Me. All were of European ancestry, the report shows.
"Have you ever had sexual intercourse with someone of the same sex?" the survey asked people whose "assigned-at-birth sex and self-reported gender match." So there's no data on transgender or non-binary people. People also weren't asked their sexual orientations, so only self-reported sexual behavior was taken into consideration.
According to the study, there are five markers "significantly" associated with same-gender attractions and behavior. "Two markers were shared by men and women, two were specific to men, and one was found only in women." But even if someone has these markers, they'd be less than 1 percent more likely to report same-sex behavior than someone born without them. The study also noted that there are "perhaps hundreds or thousands of genes, each with tiny effects" that might affect sexuality, while also linking the five markers to a rich sense of smell, increased risk-taking, and baldness in men.
"People with these markers were more open to new experiences, more likely to use marijuana, and at higher risk for mental illnesses such as depression," says the report. "LGBTQ people might be more susceptible to mental illness because of societal pressures."
Researches believe that the study shows that sexuality is impacted by a jumble of each individual's genes, environment, and life experiences, but genetics can explain between 8% and 25% of nonheterosexual behavior.
There's also no genetic evidence that proves "the more someone is attracted to the same sex, the less they are attracted to the opposite sex."
"This study is the largest and most thorough investigation into the genetics of same-sex sexual behavior to date," said Director of Genetics in the Stanley Center for Psychiatric Research at the Broad Institute of MIT and Harvard University, study author Ben Neale. "So overall, these findings reinforce the importance of diversity as a key aspect of sexual behavior."
