There is no such thing as a "homosexual gene" but a complex mix of genetics and environment impact a person's choice of same-sex sexual partners, says a large scale study associated with same-sex behaviour.
The research, which analysed data on DNA and sexual experiences from almost half a million people, found there are thousands of genetic variants linked to same-sex sexual behaviour, most with very small effects. Same-sex sexual behavior is influenced by not one or a few genes but many. Overlap with genetic influences on other traits provides insights into the underlying biology of same-sex sexual behavior
"We scanned the entire human genome and found a handful—five to be precise—of locations that are clearly associated with whether a person reports in engaging in same-sex sexual behaviour," Andrea Ganna, a biologist at the Institute of Molecular Medicine in Finland who co-led the research told Reuters.
The influence on same-sex partners comes from many genes, each with a minor role. The study looks into social or environmental factors that play a bigger part in developing the sexual behaviour of a person. "This means that non-genetic factors—such as environment, upbringing, personality, nurture—are far more significant in influencing a person's choice of sexual partner, just as with most other personality, behavioural and physical human traits, the researchers said.
The study, published in the Journal Science Aug 30 issue, is based on data from more than 470,000 people who had given DNA samples and lifestyle information to the UK Biobank and to the US genetics testing company 23andMeInc.
The findings based on survey responses and performed analyses known as genome-wide association studies (GWAS) provide insights into the biological underpinnings of same-sex sexual behavior.
Generally speaking, religious people think same-sex behaviour can be changed as they believe it is an individual choice. Researchers believe that many uncertainties are yet to be explored, including how sociocultural influences on sexual preference might interact with genetic influences.
The research funded by the National Institutes of Health and other agencies.
