Findings from a recent study published in the Journal of Experimental Social Psychology suggest we all might underestimate our gaydar abilities based on facial appearance alone. "The January 2008 study investigated people's ability to identify homosexual men from pictures of their faces alone. In an initial experiment, researchers Nicholas Rule and Nalini Ambady from Tufts University perused online dating sites and carefully selected 45 straight male faces and 45 gay male faces. All of these photos were matched for orientation (only faces shown looking forward were used) and facial alterations (none of the images contained jewelry, glasses or facial hair). To control for context, the faces were also cut and pasted onto a white background for the study. These 90 faces were then shown to 90 participants in random order, who were asked simply to judge the target's "probable sexual orientation" (gay or straight) by pressing a button. Surprisingly, all participants (both men and women) scored above chance on this gaydar task, correctly identifying the gay faces. Even more surprisingly, accuracy rate was just as good when the images were exposed at a rapid rate of only 50 milliseconds, which offered participants no opportunity to consciously process the photo." The Urban Dictionary holds no punches when describing the attributes of a gay appearance: "... gay face includes tightness around the mouth from pursing the lips, a facial expression common to gay men and womenbut not to heterosexual men. Also, gay men are more emotionally expressive, leading to a general 'tightness' and muscular activation throughout the entire face. Gay face includes an eye expression that is both surprised-looking and predatory. Eyebrows are usually arched higher than that of straight men, and eyebrow hair is manicured. There is often a slightly tan and/or leathery look to the skin, especially among older gay men." Read more here. I'd be curious to see how these statistics transfer across ethnic and cultural lines. Can they be reproduced in Japan? India? Brazil? If not, then they are less likely physical attributes and more likely behavioral. If behavior and/or learned, it begs the question: why would gay men behave in a way that made them look gay?