National Geographic Daily News
Finger length linked to aggression, musical ability, sexual orientation.

Christine Dell’Amore

National Geographic News

Published September 7, 2011

Is your ring finger longer or shorter than your index finger? The reason for the difference is in our hormones, a new study in mice shows for the first time.

Before birth, the sex hormones estrogen and testosterone control genes that in turn dictate finger length, the study found. Like us, mice naturally have both hormones in their bodies. (Get a genetics overview.)

As a result, most men have ring fingers that are longer than their index fingers, and the reverse is true in women.

Differences in finger length have been repeatedly linked to a range of human traits, from aggression to musical ability to sexual orientation. There are also connections to health problems such as autism, depression, heart attacks, and cancer.