You know what they say about men with big feet, right? Well, now you can trade that phrase in for one just a bit more cumbersome: Men whose index and ring fingers are nearly the same size are more likely to have a long penis than men whose digits don't match up. Guys, when you're done comparing your second and fourth fingers, read on: The ratio between those two digits can also reveal your risk for hormone-driven diseases including prostate cancer.
That's because a man's finger ratio can reveal his exposure to male hormones while in the womb, LiveScience reports. Previous studies have found similar links between that ratio and sperm count, heart attack risk, and other factors. The new study found that the smaller the ratio between index and ring fingers, the longer a man's stretched penis would measure. The exact reason is unknown, but researchers say testosterone in the womb appears to play a part. (Read more penis stories.)