MONDAY, July 4 (HealthDay News) -- A look at the relative length
of a man's index and ring fingers might be a good predictor of the
length of his penis, according to South Korean researchers.
They found that the ratio between the second and fourth digits
on a man's right hand seemed to correlate to the length of his
flaccid and stretched penis, with a lower index-to-ring finger
length ratio indicating a longer penis.
The key to this relationship may lie in the womb, the team
"During the fetal period, high concentrations of testosterone lead to high testicular activity, resulting in a lower digit ratio," explained a team led by In Ho Choi of Gacheon University Gil Hospital in Incheon. "In the present study, patients with a lower digit ratio tended to have a longer stretched penile length."
They added that the length of the stretched and flaccid penis
does show "a strong correlation" with an erect penile length.
The study was published July 4 in the
Asian Journal of Andrology.
The researchers noted that penile length and the
second-to-fourth digit ratio in males are "thought to be fixed
early in development." In each case, this involves a common set of
genes that regulate prenatal hormones (including testosterone) to
influence both limb development and the development of the
In the new study, Choi and colleagues compared the digit ratios
of 144 Korean men aged 20 and older who were being treated for
urological surgery. Researchers measured the index and ring fingers
of each man's right hand and compared the ratio to the length of
each man's fully stretched, flaccid penis (the latter data obtained
In a journal commentary, Denise Brooks McQuade of Skidmore
College, Saratoga Springs, N.Y., said the study results "provide
convincing support for a relationship between digit ratio and
penile length." She added that the findings might have real value
for research into clinical conditions linked to developmental
issues in men.
There's more on male sexual development at