The findings go beyond providing a new finger ratio-based pick-up line for men in bars, however; researchers say that a quick look at a man's fingers could reveal his exposure to male hormones in the womb, providing a hint about his risk for hormone-driven diseases like prostate cancer. Testosterone in the womb The prenatal hormone exposures and genetic processes that link fingers to penises are still unknown, the researchers wrote, though testosterone in the womb seems to Intitle index of penis a role. Stretched lengths ranged from nearly Intitle index of penis. The average flaccid penis length, the researchers found, was 3. The average ratio between the two fingers was 0.