“GAYDAR” colloquially refers to the ability to accurately glean others’ sexual orientation from mere observation. But does gaydar really exist? If so, how does it work? Our research, published recently in the peer-reviewed journal PLoS ONE, shows that gaydar is indeed real and that its accuracy is driven by sensitivity to individual facial features as well as the spatial relationships among facial features. We conducted experiments in which participants viewed facial photographs of men and women and then categorized each face as gay or straight. The photographs were seen very briefly, for 50 milliseconds, which was long enough for participants...