Supporting link: eaat7693
While many gene influence the same-sex attraction, genetics is could not predict someone's sexuality. An application was launched called "How gay are you?" but was taken down when people got 1400 signatures on an online petition. A study was performed on "493,001 participants from the United States, the United Kingdom, and Sweden to study genes associated with sexual orientation found that, like other behavioral traits, nonheterosexual behavior is polygenic." Though it is emphasized the polygenicity of the genetic effects on same-sex sexual behavior, we identified five SNPs whose association with same-sex sexual behavior reached genome-wide significance. Three of these replicated in other independent samples whose measures related to identity and attraction rather than behavior.
I believe that the mere thought of connecting someone sexuality to a simple test is actually insulting to humans. Our sexuality is a wide spectrum just the same way that gender and sex are different, even if genes say one thing that doesn't dictate one's sexual orientation.