People can accurately spot a man's sexual orientation at levels greater than chance with a less than half-second glance at his face, according to a study published in an upcoming issue of the Journal of Experimental Social Psychology.

Tufts University's Nalini Ambady, PhD, and graduate student Nicholas Rule asked study participants to look at photographs from online personal ads for homosexual and heterosexual men.

Participants were asked to pick whether the subjects were likely to be gay or straight. Participants accurately picked sexual orientation about 70 percent of the time within one-tenth of a second. "We don't quite know yet what it is about the face that is providing the cues," Ambady says.

She speculates that people's ability to pick up on sexual orientation cues could be tied to our evolutionary drive to find a mate. It might also be the result of implicit learning: As people mature and meet different kinds of people, they learn to associate certain facial features with sexual orientation.

Ambady is also studying whether people can correctly guess sexual orientation of men who are trying to conceal it.

—C. Munsey