For ages, the length of the ring finger has been the topic of medical attention, but ring finger length is mentioned in history far before modern medicine. Culturally, men with longer ring fingers were considered more fertile and thus more sought after as life-long mates. Increased fertility means more children and the preservation of the human race. While most women in the western world don’t think twice about the length of the male’s ring finger before choosing a mate, it could hold greater medical insight than once thought.

According to researchers at the University of Florida, the ring finger of a male is longer because of testosterone in the womb. Testosterone causes an increase in ring finger length and estrogen causes a decrease in ring finger length. Thus, women have ring fingers shorter than the index finger and men have ring fingers longer than the index finger.

Researchers tested the theory with mouse embryos. When testosterone was blocked, the digits developed with female characteristics. When testosterone was supplemented, super-male characteristics developed. When estrogen was supplemented, super-female characteristics developed.

While the study may not seem like it has a substantial footing in modern medicine, there are plenty of health conditions associated with gender and sexual development. Researchers are hoping further research will show a connection between digit length/ratio and risk of gender-specific health conditions like heart diseases and some types of cancer.

The next round of studies may be focused on the specific ratios of male and female fingers and gender-specific diseases. For instance, do women that develop breast cancer have a higher or lower index finger to ring finger ratio? Do men who develop testicular cancer show a specific range of digit ratios compared with men who do not develop the disease.

Source: John Pastor. University of Florida College of Medicine. 5 September, 2011.