Pupil Dilation Reveals Sexual Orientation

There is a popular belief that sexual orientation can be revealed by pupil dilation to attractive people, yet until now there was no scientific evidence. For the first time, researchers at Cornell University used a specialized infrared lens to measure pupillary changes to participants watching erotic videos. Pupils were highly telling: they widened most to videos of people who participants found attractive, thereby revealing where they were on the sexual spectrum from heterosexual to homosexual.

The findings were published August 3 in the scientific journal PLoS ONE.