Thursday, March 03, 2005
By Jennifer Warner, WebMD Medical News

Researchers Say the Index and Ring Fingers of Men Could Hold Some Clues

March 3, 2005 -- The next time a man angrily points a finger at you, you may want to take note of the length of that finger.

A new study shows that the shorter his index finger is relative to his ring finger, the more likely he is to be physically aggressive.
Although researchers say finger length only accounts for a small portion of the differences in men's aggressive behaviors, they explain that the results are consistent with previous studies that have linked men's finger length to the amount of testosterone a fetus is exposed to in the womb.

"More than anything, I think the findings reinforce and underline that a large part of our personalities and our traits are determined while we're still in the womb," says researcher Peter Hurd of the University of Alberta, in a news release.

Men's Finger Length Linked to Aggressive Behavior
Researchers say it's long been recognized that the length of the index (second) finger relative to the ring (fourth) finger (finger length ratio) differs between men and women. The ratio of the index to the ring finger in men is smaller, while women tend to have a bigger length difference between the two fingers.

In the study, which appears in the March issue of Biological Psychology, researchers compared hand measurements of nearly 300 male with female undergraduate students, who also completed a survey about personality and behavior traits.

The results showed that men had smaller finger length ratios than women.

In addition, the study showed that the shorter the index finger was relative to the ring finger, the more likely the male students scored higher on scales of physical aggression. However, researchers say finger length is only part of the story.

"Finger lengths explain about 5% of the variation in these personality measures, so research like this won't allow you to draw conclusions about specific people. For example, you wouldn't want to screen people for certain jobs based on their finger lengths," says Hurd. "But finger length can tell you a little bit about where personality comes from, and that's what we are continuing to explore."

SOURCES: Bailey, A. Biological Psychology, March 2005; vol 68: pp 215-222. News release, University of Alberta.