Saturday, May 05, 2007

Gimme the Finger, and I'll Tell You How Aggressive You Are

Recent research suggests that prenatal testosterone levels contribute to the relative sizes of fingers on the hand among men. Specifically, when testosterone levels are high, the second (index) digit of the hand tends to be small relative to the fourth (ring) finger. Thus, the finger-length ratio is correlated inversely with characteristics associated with elevated testosterone, such as aggressiveness. There is also some evidence that the ratio is predictive of aggressive behavior among females.

An important implication of this research is that much of our psychological makeup is determined by our biology. Finger lengths predict about five percent of the variance in aggressive traits, which is not trivial.

Of equal interest is the finding that the ratio of lengths between the fourth (ring) and fifth (little) fingers is related to neuroticism among both females and males. The ratio between second and fourth fingers also appears to be predictive of depression among men.

Given that aggressiveness among traders is plausibly related to risk seeking and neuroticism is related to emotional self control, it may well be that one's trading psychology is related to simple finger measurements. The ability to aggressively take controlled and prudent risk is surely an important component of trading success.


A Personality Test for Traders

Interpreting the Personality Questionnaire for Traders


AnaTrader said...


Going by your findings, my second index digit is slightly smaller than my fourth finger; therefore, I am not aggressive?

My fourth finger is much longer than my fifth finger; how neurotic am I?

All I know is that I finger notes quite well and that I also read and follow finger-posts of road signs.

Would be fun just to know how aggressive or emotional I am with my finger lengths, as compared with what my friends perceive of me.

Thank you

Charles said...

Oh good Lord, now you have me measuring my fingers!


Brett Steenbarger, Ph.D. said...

Hi AnaTrader,

It would be fun, indeed, to get measurements from a large group of traders to establish norms and correlations!


High Probability Trader said...

My 4th digit is longer than my index. I saw a special about this on PBS or Omnova awhile ago. Very interesting. I think the program talked about super athletes and how they are genetically gifted. Have you heard of the brain man, Daniel Tammet; a savant. Pretty interesting-

Michele said...

Oh great. This is really weird. Of *course* the first thing I did was get out a ruler and measure my fingers. And I'm not giving out the results in public :-)

My personal theory is that people with longer index fingers are better traders because they can reach the mouse button faster to get their orders in before their stubby-digited compatriots.

Charles said...

Here are my measurements:

Index Finger: 3.125"
Ring Finger: 3.25"
Little Finger: 2.5"

2D / 4D ratio: 0.96

Tip of Little Finger is just below middle of distal knuckle.