Study finds that genes influence sexuality, but there is no ‘gay gene’. There is no single gene that determines sexual orientation, but a new study has found several genetic variations that may influence sexual behaviors.
The large scale genome-wide association study puts to bed once and for all the idea of a “gay gene,” but shows that same-sex behavior is a part of natural human diversity.
“In fact, this study provides further evidence that diverse sexual behavior is a natural part of overall human variation,” the researchers explain. “Our research is intended to improve our understanding of the genetic basis of same-sex sexual behavior. It should not be misconstrued to disparage LGBTQ people.”
The study was conducted by an international group of researchers in collaboration with activists and advocacy groups to help answer the question of why people differ in sexual behaviors.
DNA data from the UK Biobank, the genetic testing company 23andMe, the National Longitudinal Study of Adolescent to Adult Health, Molecular Genetic Study of Sexual Orientation, and The Child and Adolescent Twin Study in Sweden were reviewed and analyzed for the study.
By combining several large-scale studies, the researchers focused on what role genetics might play in shaping certain same-sex behaviors.
Data from 477,522 individuals were included in the research, and participants provided DNA samples as well as answers to questions on sexual identity, number of same-sex encounters, and sexual attraction.
The researchers identified five genetic variants associated with same-sex behavior.
“By incorporating DNA and personal information from nearly half a million people, our study is the first to include enough people to be able to link specific genetic variants and same-sex sexual behavior with demonstrable statistical confidence,” the researchers wrote.
This is the first time such genetic markers have been identified. However, it’s important to note that the human genome is made up of millions of genetic markers, each with its own small contribution to different behaviors.
The researchers also made sure to emphasize that the genetic variants are linked only to same-sex behaviors and that the study is not focused on identity or orientation.
While these variants were linked to same-sex behaviors, none of them clearly predicted these behaviors and only accounted for eight to 25 percent of the genetic variation in same-sex behavior for men and women.
There are several limitations to the study, including that much of the data relied on self-reported information and that there are other non-genetic environmental factors that must be considered.
“It just shows us that same-sex sexual behavior is much more complex than this idea of having just one gene influencing it all,” Eric Vilain, director of the Center for Genetic Medicine Research at Children’s National Health System, told the Washington Post. “It shows that there are genetic factors, which we had suspected long ago … but it also shows those genetic factors do not tell the whole story.”
The study was published in the journal Science.
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