Nobody knows just how a person becomes gay or lesbian, whether it's a choice or triggered by genes.
The biological root of sexual orientation is a matter of heated debate among scientists at the moment. He claimed this showed that sexual orientation was biological . Then, in July 1993, Dean Hamer of the National Cancer Institute in Washington, DC, reported that he had found a genetic factor called Xq28 that seemed to help determine male sexual orientation. Later, he looked at 33 more sets of brothers and found that 67 percent shared the region. But no one since has been able to duplicate Hamer's findings.