The ratio of the length of a man’s index finger to that of his ring finger may seem like a strange thing to measure, but new research suggests that it’s linked with penis size. The lower the ratio, the longer the penis.
The new study was conducted on 144 Korean men who were hospitalized for urological surgery. A researcher measured the patients’ penile length — flaccid and stretched — just after they went under anesthesia for their operations. A different researcher measured the men’s finger lengths, in order to prevent knowledge of one measurement unconsciously affecting the other.
They data suggested that those with a lower ratio, whose index finger (or second finger, 2D) was shorter than the ring finger (or fourth finger, 4D), had a longer stretched penis length, which is well correlated with erect size.
“Based on this evidence, we suggest that digit ratio can predict adult penile size,” the researchers, led by Dr. Tae Beom Kim of Gachon University in Incheon, Korea, wrote.
Previous studies have linked the so-called 2D:4D ratio of finger length with exposure to the sex hormones estrogen and testosterone in the womb. So it’s plausible that the same exposure may affect penis length.