You know what they say about men with big hands and feet. It is all old wives’ tales, of course. The true measure of a man’s penis is his ring finger. That is what Korean researchers have found in a recently published study of 144 men. It is even true in mice.
This research, the results of which have been published in the Asian Journal of Andrology, was conducted by Gachon University under the leadership of Dr. Tae Beom Kim and involved measuring the fingers and the flaccid as well as the extended penises of 144 anesthetized men.
What the researchers found was that the ratio between ring finger and index finger lengths was indicative of penis size. Men’s index fingers are generally shorter than their ring fingers, so a long ring finger in itself does indicate endowment. The secret is in the ratio. The larger the difference in length between ring finger and index finger, the larger the penis when extended. The team of researchers was working under the assumption that the extended anesthetized penis is equivalent in size to the erect penis.
“Based on this evidence, we suggest that digit ratio can predict adult penile size,” said Dr. Tae Beom Kim in summary of the team’s theory, “and that the effects of prenatal testosterone may in part explain the differences in adult penile length.”
The idea that prenatal testosterone might affect both finger and penis length has been simultaneously explored by another team of researchers. This study, published on September 19 in Proceedings of the National Academy of Sciences, focused on mice. Mice are known to have finger ratios similar to humans, which is why they were chosen for this study.
The researchers exposed one group of mouse embryos to high levels of testosterone and another to oestrogen. The mice exposed to male hormones during this crucial developmental phase had proportionally longer fourth digits – that is to say, ring fingers. The mice that were exposed to large quantities of female hormones, on the other hand, developed proportionally small fourth digits. Among humans, like mice, women generally have index and ring fingers of similar length, with the index finger more likely to be longer.
If this still sounds like an old wives’ tale, it should be noted that digit ratio has previously been the subject of numerous studies on sexual development and sexual behavior. Amongst others, one controversial study in 2000 suggested that women with a more typically male ratio were more likely to be lesbian. Another study from 2010 indicated that primate species in which the males generally have smaller index to ring finger ratios are less likely to be monogamous.