They say the eyes don't lie, and new research suggests that the old saying is true when it comes to attraction.
Many decades ago, gay men relied on what another man was wearing (and which side they were wearing it on) to tell them whether he was gay or straight. But we moved on from swapping colored scarves to relying on good old fashioned intuition, also known as gaydar.
Still, gaydar had its limitations. Intuition could only suggest so much: whether someone was gay or straight, or to the finely tuned observer, a little more than curious. Even then, with his sexuality cleared up, there was still no way of knowing whether he was attracted to you or not.
Our courting habits may change thanks to research conducted at Cornell University. Lead researcher and developmental psychologist Ritch Savin-Williams and team conducted a large scale study to determine whether pupil dilation could signal attraction. The study was published this month in the journal PLoS ONE.
What they found was a spot on. Our pupils do dilate when we encounter a person we're attracted to.
Savin-Williams and group recruited 165 men and 160 women, including gay, straight and bisexual participants. They found that, as expected, the gay men's pupils dilated when shown a minute of man on man porn. The women had the same reaction to erotic images of men, and the straight men at videos of women. The pupils of the bisexual participants dilated in response to both sexes.
"So if a man says he's straight, his eyes are dilating towards women," Savin-Williams told LiveScience. "And the opposite with gay men, their eyes are dilating to men."
Since pupil dilation is a part of the autonomic nervous system, which controls involuntary actions like breathing, our eyes respond to other stimuli as well, like a favorite piece of art or at the sight of a favorite relative.
There are definite advantages to this discovery, namely solving the mystery of mutual attraction. The formula's just been simplified: Cruise him, when he looks back, check out his eyes, they dilate, he's probably interest (or simply attracted to your shirt).
Savin-Williams's study isn't the first attempt by scientists to identify which senses and physical responses reveal our attractions. For instance, in 2008 researchers at the University of Pennsylvania's Monell Chemical Senses Center asked gay men to sniff the underarm sweat of other volunteers. They found, in pattern, that the gay participants could recognize the "scent" of other gay volunteers.
Similarly, researchers at Karolinska University in Sweden found that a steroid compound that men secrete in their sweat, called androstenone, excited areas of the brain that control sexual behavior in gay men, but left the brains of straight men unaffected.
And in 2010, Dutch researcher Dr. Lorenza Colzato of Leiden University observed that identifying who's gay or straight is a matter of detail. When asked to comment on photographs of outlines of squares and circles, gay participants were found to possess a greater sense of detail than the straight volunteers.
Are there other physical cues we should be aware of? About.com Guide to Psychology Kendra Cherry says there's even more to the behavior of our eyes than outing our attractions.
For example, Cherry writes:
"When a person looks directly into your eyes when having a conversion, it indicates that they are interested and paying attention. However, prolonged eye contact can feel threatening. On the other hand, breaking eye contact and frequently looking away may indicate that the person is distracted, uncomfortable, or trying to conceal his or her real feelings."
What about blinking? "Blinking is natural, but you should also pay attention to whether a person is blinking too much or too little," Cherry adds. "People often blink more rapidly when they are feeling distressed or uncomfortable. Infrequent blinking may indicate that a person is intentionally trying to control his or her eye movements."
So, the next time you're wondering if the person next to you shares an attraction, let your senses and his eyes do the talking.