Lawrence LeBlond for redOrbit.com – Your Universe Online
A person´s eyes can often say what they are thinking, what emotions they are going through, and even if they are lying or telling the truth. Now, you may even be able to tell if a person is gay or straight, according to new research from Cornell University.
The researchers involved in the study said their findings indicate that someone´s sexual orientation can be revealed by their pupil dilation. Scientists say that when a person becomes aroused, his or her pupils will shoot open, helping those on the prowl to know whether or not the person is making eyes at them.
Researchers have long been able to track a person´s level of excitement through pupil dilation. When a person sees a familiar face the pupils open a little. The same goes for seeing a cute puppy or kitten. But this is the first time researchers have been able to read optical reflexes to determine what gender a person really has his or her eye on.
The Cornell scientists, publishing their work in the journal PLoS ONE, used a special infrared lens to measure pupillary changes in participants watching erotic scenes. They found the pupils were highly telling: they widened the most for videos of people they found attractive, revealing where they were on the sexual spectrum from hetero to homosexual.
Past studies have explored sexual orientation either by asking people about their sexuality, or by using physiological measures such as assessing genital arousal. These previous studies, however, have come with a certain level of biasness.
Cornell´s study, conducted by Dr Ritch Savin-Williams and Gerulf Rieger, monitored 165 men and 160 women, including gay, straight, and bisexual accomplices.
During the video-pupil dilation study, each person was observed as they viewed one-minute videos each of a man masturbating, a woman masturbating, and a neutral landscape scene.
For men, the results showed just what the scientists expected: straight men reacted to the images of the women, gay men to the images of the men, and bisexuals to scenes of both. However with women, the results were much more complex. Gay females had pupil dilation after seeing sexual images of other women but straight women dilated similarly in response to erotic scenes of both sexes.
Savin-Williams noted that this does not mean that all straight women are secretly bisexual; what it could mean is that their subjective arousal doesn´t necessarily match their body´s arousal. Researchers are not exactly sure why this would be, but some do theorize that the response is a survival mechanism due to risk of female rape. The body may be responding to a sexual stimulus, regardless of its appeal, for purposes of protection.
Lead author Rieger, said: “With this new technology we are able to explore sexual orientation of people who would never participate in a study on genital arousal, such as people from traditional cultures. This will give us a much better understanding how sexuality is expressed across the planet.”
This study also feeds into a long-lasting debate over male bisexuality. Previous beliefs were that most bisexual men do not base their sexual identity on physiological arousal but more on romantic or identity issues. However, the researchers found that substantial pupil dilations found in bisexual men indicate they are indeed aroused by scenes of both men and women.
“We can now finally argue that a flexible sexual desire is not simply restricted to women — some men have it too, and it is reflected in their pupils,” said Savin-Williams. “In fact, not even a division into ‘straight,’ ‘bi,’ and ‘gay’ tells the full story. Men who identify as ‘mostly straight’ really exist both in their identity and their pupil response; they are more aroused to males than straight men, but much less so than both bisexual and gay men.”
The researchers hope to further study this issue using pupil dilation and genital measurements simultaneously. However, many people find it uncomfortable having their genitals put under scrutiny, acknowledged the researchers.
They do remain confident that their new measure will aid in understanding these groups better and point to a range of sexualities that has been ignored in previous research.