The study found that women’s eyes dilated when they viewed a man and a woman being sexuality intimate, and when two women were sexually intimate.

Lesbian are more aroused to their preferred sex than the other sex, a pattern normally seen in men.

A similar phenomenon was seen in men. Talking to Broadly, study author Ritch C Savin-Williams, who is also the Director of Developmental Psychology at Cornell University, said:

We show straight men a picture of a woman masturbating and they respond just like a straight guy, but then you also show them a guy masturbating and their eyes dilate a little bit. So we’re actually able to show physiologically that all guys are not either gay, straight, or bi.