Are Gaydars Real? Yes.
William Lee Adams wrote a thesis as an undergraduate at Harvard on the ability to identify homosexuals. He found that gay men and straight women were more accurate in identifying other homosexuals. In addition,
“Gay men and women not only made more accurate assessments, they were efficient, too: It took about 2 seconds for gays to decide whether a person was straight or not.”
So why do gay men and straight women possess this ability? Perhaps there are biological roots for this. Since gay men will not have their affection towards other men reciprocated by straight men, maybe they have developed cues to distinguish those who are like themselves. As for why women can tell gay from straight, it’s still a mystery…Source: http://www.psychologytoday.com/articles/200510/queer-eyes-blips-the-gaydar