This idea, born in the 1990s, argued that there was a “gay gene” as predictable as determining the color of our eyes, or our blood type. The most extensive study ever conducted on 480,000 people, today refutes this principle, demonstrating that loving a person of the same sex is not defined by a single gene, but by a complex mixture genetic and environmental influences. The details of this work are published in the journal Science.
“This is a natural and natural aspect of the variation of our species,” says Ben Neale, Stanley Center for Psychiatric Research and lead author of this study. This should also support the position that we should not try to develop remedies for homosexuality. It’s not in anyone’s interest. “
Genetics plays a minority role
For this work, the researchers focused on the genetic profiles of people from the United States and the United Kingdom. They then discovered five specific genetic variants significantly associated with homosexual behavior. But when combined, these variants account for less than 1% of a person’s attraction to their sex. For researchers, there would be hundreds, if not thousands of other markers involved, that future analyzes could one day isolate.
“As a result, it is impossible to predict an individual’s sexual behavior from his or her genome,” the researcher continues. Sexual orientation does have a genetic component, but this component “does not depend on a single gay gene,” they say. Many small genetic effects distributed throughout the genome are also involved. ” The environment in which a person evolves during his / her life also plays a role. But it remains challenging to measure.
We also learn that these five isolated genetic variants, related to attraction to a person of the same sex, are placed in unusual places. One of them seems indeed located in a DNA segment containing several genes related to smell, for example. “We know that smell is closely linked to sexual attraction, but its links to sexual behavior are unclear,” notes Andrea Ganna, Massachusetts General Hospital and co-author of the study. Another was associated with male pattern baldness, which suggests a connection to the regulation of sex hormones.