April 5, 2008

Sex and Greed Linked in the Brain

Scientists at Northwestern and Stanford Universities have found that both sex and financial risk are associated with the same areas in the brain. 

The researchers conducted their study in young men, and discovered these men were more likely to take large financial risks after being shown erotic pictures than if they were shown pictures of scary or neutral objects, such as a stapler or a snake. Using brain scans, the researchers determined that the arousing pictures lit up the same area of the brain that activates when financial risks are taken.

"You have a need in an evolutionary sense for both money and women. They trigger the same brain area," said Camelia Kuhnen, a Northwestern University finance professor who conducted the study with a Stanford University psychologist.

The scientists performed their study at Stanford University with 15 young, heterosexual men, and used brain scans to focus on the V-shaped nucleus accumbens, the sex and money hub near the base of the brain that plays a key roll in how people experience pleasure.

When this area of the brain was activated by erotic images, the researchers found the men were far more likely to bet high on a random chance game that would earn them either a dollar or a dime.  Each man made more than 50 gambles under brain scans.

Brian Knutson, a Stanford psychologist and the study's lead author, said it's all about the power of emotion and arousal and our financial decisions.  The trigger doesn't necessarily have to be sex, it could be a winning lottery ticket or even chocolate.

"It didn't matter if the sexy woman didn't tell you anything about the odds of winning a roulette game," Knutson told the Associated Press.

"What really matters is that the sexy woman is having an emotional impact. That bleeds over into your financial decisions."

Kuhnen said that while the study involved only men, the same link could hold true for women, but they didn't test it because it's more difficult to find erotic images that appeal to many different heterosexual women compared to heterosexual men.

Kevin McCabe, a professor of economics, law, and neuroscience at George Mason University who was not involved in the study, said the link between sex and greed goes back hundreds of thousands of years to men's evolutionary role as a provider to attract women. 

"Risk-taking is a natural way of increasing your relative success, but, of course, there's a downside to it, what we're seeing right now in the economy," McCabe told the Associated Press.

Phil Flynn, a former Chicago commodities floor trader and current analyst at Alaron Trading Corp., said the study's results corroborate real life on the trading floor.

"I'm not shocked that it may be part of the deal," Flynn told the AP on Friday.

"When you talk about all the euphemisms for trading (on the floor), they can be used for sex as well," he said, referring to sayings such as "massaging the market" and "hardcore", the cleanest he and his colleagues could come up with.

The study supports other research that found men shown a pornographic movie were more likely to make riskier sexual decisions.  Another study suggested straight men think less about their financial future after being shown pictures of pretty women.   A Harvard University study not yet published discovered a link between financial risk-taking and higher testosterone levels.

But the Stanford study went deeper, using functional magnetic resonance imaging machines in part of a new but growing field called neuroeconomics.  The field attempts to take the hard-wired science of brain biology and mix it with the softer sciences of economics and psychology to determine how people make financial decisions.   

A previous study conducted by the same team found that the brain's reward area activated at about the same time as risky decision-making.

The erotic pictures experiment was designed to determine cause and effect.  The answer, the researchers found, was that the lighting up of the brain's reward area with the soft-core pictures caused the risky decision making. 

"The more activation there you have, the more prone you are to taking more risk," Kuhnen said. "It could be a feedback loop."

The researchers found that the photos of the snakes and spiders activated those parts of the brain associated with pain, fear and anger, and that those who viewed the photos were more likely to bet low.

Terry Burnham, a Harvard economist and author of the book "Mean Genes", said the whole thing could be summed up in a famous line from the movie "Scarface."

"In this country, you gotta make the money first. Then when you get the money, you get the power. Then when you get the power, then you get the women."

The Stanford study was funded by the National Institutes of Health, and is published in the current edition of the peer-reviewed journal NeuroReport.  The full report can be viewed here.

Additional Information on Stanford's Symbiotic Project on Affective Neuroscience can be viewed at http://psychology.stanford.edu/span/.


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