Men, you might want to check the size of the index and ring fingers on your right hand.
If your index finger is shorter than your ring finger, you not only are more likely to have a long penis, but your finger size may also provide your doctor with a hint about your risk for testosterone-related diseases like prostate cancer.
Despite all the sexual jests about what a man's finger size really reveals, a team of South Korean researchers at Gachon University Gil Hospital say the ratio between the second and fourth finger may be linked to hormone exposure in the womb.
The study, published this week in the Asian Journal of Andrology, studied 144 male volunteers over the age of 20 who were undergoing urological surgery for conditions that didn't affect penile length.
The researchers measured the subjects' right hands -- thought to be more sensitive to the influence of testosterone -- as well as stretched penile length (this part was done while the subjects were under anesthesia).
The team found that it wasn't simply finger length, but the comparison of length between the second and fourth finger that can predict penile length. "According to our data...the shorter index (second) finger than ring (fourth) finger you have, the longer stretched penile length you have," urologist Tae Beom Kim told Reuters.
The ratio of finger length in men is an indication of "the effects of prenatal testosterone," the researchers wrote in the study.
This idea of finger length being linked to testosterone is not a new one.
A number of studies have been done on the subject, including a study last year by Britain's Institute of Cancer Research that found that men whose index finger is longer than their ring finger were found to be one-third less likely to develop prostate cancer. The risk reduction was even greater in men under 60, the researchers said.
The British researchers suggested that relative finger length could be used as a simple test for prostate cancer risk, helping doctors screen more at-risk men.
In an editorial accompanying the Korean study, biologist Denise McQuade of Skidmore College in New York acknowledged the jokes about how "your hands give away your hotness."
"Hotness aside," she wrote, the research seemed to show that finger size ratio was an easy way for doctors to determine potential hormone-related risk levels in men.
And that's no laughing matter.
Photo credit: Monica Arellano-Ongpin via flickr.com