A new saliva test that can purportedly determine whether a man is gay or straight is scientific, based on genetics and surprisingly accurate! It was recently presented at the annual meeting of the American Society of Human Genetics, which is happening this week in Baltimore, Md.

The saliva test works on men, but not on women or bisexuals. It is based on Tuck C. Ngun's research on homosexuality involving male identical twins, on which HNGN previously reported.The test relies on an algorithm developed out of the epigenetic markers taken from a sample of 37 pairs of twins, each with homosexual and heterosexual orientations. Such markers identify gene regions that distinguish the homosexual from the heterosexual twin.

The saliva test can incredibly predict the subjects' sexual orientation 67 percent of the time, New Scientist reports."The predictive test needs replication on larger samples in order to know how good it is, but in theory it's quite interesting," said Michael Bailey from Northwestern University.

Ngun's saliva test is just one of several discoveries that support how homosexuality is determined by several variables. The test is genetic in nature. There are those that show environmental influence such as the fraternal birth order effect, wherein it is found that a woman's first male pregnancy increases the chances for the son to be homosexual by as much as 33 percent, according to Popular Science.