Digit ratio predicts penis length

In addition to its relationship to a variety of diseases, the length ratio of the second and fourth fingers also correlates with stretched penile length in men.

Written byJef Akst
| 1 min read

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FLICKR, JON GENIUS

You know the old wives tale about the size of a man's feet? Well, science has uncovered evidence that his hands may hold a similar predictive power. According to a study published online yesterday (July 4) in the Asian Journal of Andrology, the length of a man’s fingers is indicative of his stretched penile length—the shorter the second finger is relative to the fourth, the longer the penis. The 2D:4D ratio of the male hand has previously been linked to a variety of biological characteristics, including general attractiveness and the risk of developing certain diseases such as prostate cancer. These correlations are likely due to differences in prenatal testosterone levels and the sensitivity of the androgen receptor, both key factors in penis development. The authors ...

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Meet the Author

  • Jef (an unusual nickname for Jennifer) got her master’s degree from Indiana University in April 2009 studying the mating behavior of seahorses. After four years of diving off the Gulf Coast of Tampa and performing behavioral experiments at the Tennessee Aquarium in Chattanooga, she left research to pursue a career in science writing. As The Scientist's managing editor, Jef edited features and oversaw the production of the TS Digest and quarterly print magazine. In 2022, her feature on uterus transplantation earned first place in the trade category of the Awards for Excellence in Health Care Journalism. She is a member of the National Association of Science Writers.

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