Finger Ratio: Science or Palm Readings?

Jan. 13, 2008— -- Men who have a shorter index finger relative to their ring finger proved to be better at high-stakes, fast-paced stock trading than men with relatively longer index fingers, according to a new study.

John Coates, the lead author on the stock trading study, published yesterday in the journal Proceedings of the National Academy of Sciences, was initially uncertain that digit ratios would tell him anything useful.

"I didn't put much stock in it to tell you the truth, until I saw the results -- I almost fell out of my chair," said Coates, of the Judge Business School and department of physiology, development, and neuroscience at University of Cambridge, England.

In the study, researchers measured the right hands of 44 male stock traders who were engaged in a type of trading that involved large sums of money, rapid decision-making and quick physical reactions.

Over 20 months, those with longer ring fingers compared to their index fingers made 11 times more money than those with the shortest ring fingers. Over the same time, the most experienced traders made about nine times more than the least experienced ones.

Looking only at experienced traders, the long-ring-finger folks earned five times more than those with short ring fingers. Coates said he turned to the digit ratio because he was searching for a convenient marker for a person's sensitivity to testosterone.

More accurate physical markers of testosterone sensitivity include a measurement in the inner ear, and the "ano-genital" distance, but Coates thought stock traders were more likely to offer up their hands to measurements than their rear ends.

Exactly how or why is unclear, but studies have shown the relative length of the ring finger is related to the amount of androgens (testosterones) present in a baby's body during the 8th to 19th week of pregnancy.