A group of Korean researchers working out of Gachon University, Gil Hospital, Incheon, and Seoul National University College of Medicine, Seoul, Korea, have found that measuring the second and fourth fingers on the right hand of a man, and then calculating the ratio between their lengths serves as a very accurate predictor of penis length. They have published their findings in the Asian Journal of Andrology.
The team, comprised of urology researchers, set out to find reasons for differing penis length in men, as many have come to believe that there is a process that goes on while still in utero that is known to effect certain human body parts, one of them being finger length. It is thought that testosterone and estrogen levels have an impact on growth patterns on a fetus. What’s not been documented however, is why certain fingers grow more than others when exposed to such hormone levels. The idea for the study came from a discussion of whether longer exposure times in utero resulted in longer second and fourth fingers, meaning they became closer in length. Afterwards, the idea of whether the same phenomenon might occurr with the penis, since its growth has also been linked to hormone levels in fetuses, arose, and the team set up an experiment to find out.
To conduct the study, 144 men age 20 and older who were already in the hospital for scheduled surgery not related to their hands or genitals were asked to give their permission to have their hands and genitals measured while under anesthetic. Men with medical conditions known to impact finger and/or penis length were ruled out. Fingers were measured using calipers from base to tip. Penises were measured in both their flaccid and stretched-to-full-length state, using highly accurate plastic rulers. Measurements of hands and genitals were done by different groups to ensure no bias was introduced. The end result was that the calculated ratios of length of the fourth and second finger proved to be a very highly accurate way to estimate stretched penis length, which in plain English means, the closer the second and fourth finger are to each other in length, the longer the penis.
The research team noted that in addition to finding 4:2 finger ratios to be excellent predictors of stretched penis length, that total body height was the best indicator of flaccid penis length, i.e. taller men almost always had longer flaccid length than shorter men. They offer no suggestions as to why this may be so, but point out that flaccid penis length is almost never a reasonable indicator of stretched length.