No one gene that determines a person’s sexual orientation

There is no one gene that determines a person’s sexual orientation, but genetics – along with environment – play a part in shaping sexuality, a massive new study shows.

Researchers analysed DNA from hundreds of thousands of people and found that there are a handful of genes clearly connected with same-sex sexual behaviour. The researchers say that, although variations in these genes cannot predict whether a person is gay, these variants may partly influence sexual behaviour.

Andrea Ganna, lead author and an instructor at Massachusetts General Hospital and Harvard Medical School, said the research reinforces the understanding that same-sex sexual behaviour is simply “a natural part of our diversity as species.”

The new study, published Thursday in the journal Science, is not the first to explore the link between genetics and same-sex behaviour, but it is the largest of its kind, and experts say it provides one of the clearest pictures of genes and sexuality.