Success in the City may go hand in hand with finger length
The length of a man's fingers may predict his success in the City, research findings suggest.
Scientists at Cambridge University found that financial traders whose ring fingers are longer than their index fingers make the most money.
The link could be down to testosterone exposure in the womb, Proceedings of the National Academy of Sciences says.
This exposure may improve rapid decision-making skills and has been linked with aggression.
The same ring-to-index finger ratio, which is determined in the womb, has previously been associated with success in competitive sports.
Researcher John Coates and his team reported last year that testosterone seemed to boost short term success at finance after they found City traders with higher levels of the male hormone in the morning were more likely to make an unusually big profit that day.
Their latest findings are based on a study of 44 men working as traders in London, some of whom earned more than Â£4 million a year.
Over 20 months those traders with longer ring fingers made 11 times more money than those with the shortest ring fingers relative to their index fingers.
This "biological" impact on success was about equal to years of experience at the job. The most experienced traders made about nine times more than the least experienced ones.
When the researchers looked only at the experienced traders, those with longer ring fingers earned far more than those with shorter ring fingers - Â£838,000 compared to Â£154,000 on average, respectively.
The scientists believe that exposure to the "aggression" hormone testosterone in the womb may have improved the traders' concentration and honed reflexes necessary to follow prices and make trades on extremely short notice.
This suggests that success on the financial markets is influenced by biology as much as experience, the researchers told PNAS.
Meanwhile, Belgian researchers have found men with longer ring fingers become less "socially minded" - less willing to give money to a fellow participant - after watching aggressive movies.
The reverse was also true - those with shorter ring fingers gave away the most money.
Lead researcher Kobe Millet said: "These results tell us that levels of testosterone people are exposed to before birth go on to affect their behaviour throughout their lives."
He said studies suggested similar associations with finger length are also seen in women.