Genetic analysis of the data of half a million people led to the conclusion that there is no single gene responsible for homosexuality, writes the BBC.
In a study whose results were published in the journal Science, data from the Biobank of Great Britain and the American biotechnology company 23andMe were studied.
Some genetic combinations associated with same-sex relationships were discovered, but genetic factors determined homosexual behavior by only a quarter.
Researchers scanned the genomes of 409,000 people registered in the British Biobank project, and 68,500 people registered in the 23andMe genetic company. Study participants were also asked about the gender of their partners.
As a result, researchers from Harvard University and the Massachusetts Institute of Technology came to the conclusion that from 8 to 25% of homosexual behavior in society is determined by genetic factors – but not just one gene.
It was found that 5 combinations of genes are associated with attraction to people of their gender, one of them is associated with the sense of smell, the other is associated with sex hormones. But together they accounted for less than 1% of homosexuality.
“There is no single homosexuality gene, so a genetic test of the likelihood of a person having same-sex relationships will not work,” says Ben Neal, a professor of analytic and translational genetics at the Massachusetts hospital who worked on the study.