Finger length may predict financial success
By RANDOLPH E. SCHMID
AP Science Writer
WASHINGTON (AP) -- The length of a man's ring finger may predict his success as a financial trader. Researchers at the University of Cambridge in England report that men with longer ring fingers, compared to their index fingers, tended to be more successful in the frantic high-frequency trading in the London financial district.
Indeed, the impact of biology on success was about equal to years of experience at the job, the team led by physiologist John M. Coates reports in Monday's edition of Proceedings of the National Academy of Sciences.
The same ring-to-index finger ratio has previously been associated with success in competitive sports such as soccer and basketball, the researchers noted.
The length ratio between those two fingers is determined during the development of the fetus and the relatively longer ring finger indicates greater exposure to the male hormone androgen, the researchers noted.
Previous studies have found that such exposure can lead to increased confidence, risk preferences, search persistence, heightened vigilance and quickened reaction times.
In a separate study last year, Coates and colleagues reported that the hormone that drives male aggression and sexual interest also seemed able to boost short term success at finance.
They studied male financial traders in London, taking saliva samples in the morning and evening. They found that those with higher levels of testosterone in the morning were more likely to make an unusually big profit that day. Testosterone, best known as the male sex hormone, affects aggression, confidence and risk-taking.
In the new study, the researchers measured the right hands of 44 male stock traders who were engaged in a type of trade that involved 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 9 times more than the least experienced ones.
Looking only at experienced traders, the long-ring-finger folks earned 5 times more than those with short ring fingers.
While the finger ratio, showing fetal exposure to male hormones, appears to signal likely success in high-actively trading that calls for risk-taking and quick reactions, it may not indicate people who would do well at other sorts of financial activities, the researchers said.
Some traders require additional skills on dealing with clients and sales workers.
And the advantage may even reverse for some, Coates team said, such as traders taking a more analytical and long-term approach to the markets.
One study, which looked at average finger ratios in university departments found that faculty from math, science and engineering exhibited longer index finger ratio, rather than ring finger, they noted.
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 £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 - £838,000 compared to £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.
Recently, scientists in North America and Europe have looked to the relative lengths of index and ring fingers for clues about a variety of characteristics, including musical ability, athletic prowess and, in a study just released, osteoarthritis risk.
The researchers believe that the difference between the two fingers' lengths signifies the level of testosterone exposure in the womb. The longer the ring finger compared to the index finger, the thinking goes, the higher the exposure.
Scientists express the fingers' relative lengths as a ratio, computed by dividing index finger length by ring finger length. Men tend to have longer ring fingers than index fingers, or ratios less than 1, and women tend to have index and ring fingers of equal length, or ratios of 1.
Don't worry if your finger ratio looks to be more like that of the opposite sex, says Marc Breedlove, professor of neuroscience at Michigan State University. There's less of a sex difference in finger ratios than there is in height, he says.
"I wish it was a better marker … of prenatal testosterone," he says. "It's not a very good correlation. It's easy to find women who have more masculine ratios than some men."
Still, Breedlove says, short of a time machine, he doesn't know of a better tool with which to assess prenatal testosterone exposure.
Just made the connection
Giacomo Casanova, the famous womanizer who died in 1798, observed in his memoirs that the ring finger is longer than the index finger.
But it wasn't until 1998 that British psychologist John Manning first linked the index-ring finger ratio to prenatal hormone levels.
"It's been known for about a hundred years that there's this tiny sex difference in the ratio, but it's so small that one wouldn't think it's particularly important," says Manning, who recently retired from the University of Central Lancashire and is now associated with Southampton University.
Manning had been studying whether body asymmetry — in which, say, a finger on one hand is longer than the same finger on the other hand — is linked to such traits as fertility. He noticed that in young boys, but not young girls, ring fingers tended to be longer than index fingers. He speculated that prenatal hormone exposure played a role.
"The sex difference almost certainly arises before birth," Manning says, adding that it can be seen in fetuses at nine weeks' gestation, "and it doesn't change at puberty."
Since 1998, Manning has published studies suggesting that male symphony orchestra musicians have lower finger ratios than less-musical men, that heterosexual men have lower ratios than homosexual men and that people with lower ratios tend to do better on certain tests of spatial ability.
But "the links with sports are the strongest I've found," Manning says. "They're particularly strong with endurance running." He theorizes that prenatal testosterone benefits the cardiovascular system.
"I think the goal is to see whether you can find any evidence that prenatal testosterone makes any difference at all," Breedlove says. "If you do see a relationship between the digit ratios and whatever symptom you're looking at, then you have to wonder."
For example, he says, "how might prenatal testosterone influence how your joints feel when you're 55 years old? Ten years ago, no one would have even asked the question."
The link to osteoarthritis
British rheumatologist Michael Doherty and his collaborators at the University of Nottingham did just that in a study in the January issue of Arthritis & Rheumatism.
Osteoarthritis is more common in men, Doherty says, and, he and his co-authors write, increased activity and physically demanding sports could contribute to the condition through repetitive joint trauma. So it makes sense that a lower finger ratio, thought to be more common in men and in athletic individuals, would be linked to a higher osteoarthritis risk.
By comparing about 2,000 osteoarthritis patients with about 1,000 people without osteoarthritis, Doherty's team found that is indeed the case. The strongest link: osteoarthritis of the knee in women whose ring fingers were longer than their index fingers.
Even after accounting for such osteoarthritis risk factors as physical activity and higher current testosterone levels, Doherty and his co-authors found that a relatively long ring finger was itself a risk factor. If they had studied elite athletes, though, perhaps they would have seen a link between physical activity and osteoarthritis risk, Doherty says, noting, "we're just one study."
Although finger ratio is easily measured, says Michael Peters, a psychology professor at Ontario's University of Guelph, "I don't see it becoming a powerful diagnostic predictor anytime soon."
But, Manning says, one country hopes the tool will help identify future athletes. He is working with Qatar's Aspire Sports Academy, whose vision, according to its website, "is to discover the best young sporting talent … and transform them into world-renowned champions."
Manning's goal: to prove that finger ratio at age 10 predicts athletic ability at age 18.
p/s photo: Zhang Ting