New research suggests that the dilation of our pupils says a lot about our sexual desires. Researchers at Cornell University found that participants’ pupils widened most in response to erotic videos of people they found attractive. Straight men’s pupils were much wider when they saw videos of men than when they watched women, but straight women responded to both sexes—which adds to the heap of evidence that women’s sexuality exists along a spectrum. “Heterosexual,” “bisexual,” and “lesbian” are just labels we choose, usually representing our dominant preference. What those labels actually represent for each individual comes in every color of the rainbow.