I came across an interesting article on BBC (Finger length 'key to aggression' ) today and The Economist has a similar article ( Neuroeconomics: Digitally enhanced ). They report a positive correlation between the length of mens' ring fingers and their success in high-stress securities trading. Actually, the more correct comparison s between the ratio of the ring to index finger and success/aggression. In women, the ring and index fingers are comparable, however the ring finger is significantly longer than the index finger in men. In this study, the researchers only looked at men's fingers. Apparently the level of testerone in a fetus is exposed to during pregnancy affects length of fingers as well as the level of aggression. More aggressive traders tend to have longer ring fingers and they happen to be more successful, after factoring out the effect of experience. They also reached a similar conclusion when looking at college students. Having a short ring finger...