If you’re wondering just what a tubercle (pronounced TOO-ber-kel) is—don’t worry, we also had to look it up—it’s that little puffy spot in the middle of your upper lip that can point out if it’s especially pronounced. We suppose you could find a mirror and analyze yours, but that’s not really important: It’s women's lips you should be looking at if you’ve got sex on your mind.
Researchers at the University of the West of Scotland analyzed the results of an online survey that asked women about the shape of their pout and if they'd ever had a vaginal orgasm. Though most women said they had an orgasm, of the ones who didn't, there were slightly more flat tubercles.
Just like you, the researchers are totally confused as to why the link exists in the first place. But it might have something to do with fetuses. Whatever shapes a fetus’s tubercle may also shape the same neural circuits that affect vaginal orgasm by the time that fetus grows into a woman, says co-author Rui Miguel Costa, M.A., a grad student at the University of the West of Scotland.