CLAREMONT - Stock traders whose genetic makeups can help them make healthy decisions about risk-taking may be better suited for a long career on Wall Street than others who may be predisposed to a "cowboy" way of doing business, new research suggests.

"I don't want the guy who is going to stay awake for four days and drink Red Bull and make trades across three markets in three time zones," Claremont Graduate University professor Paul Zak said.

Zak and two graduate students published their research in the January issue of PLoS One, an online science journal. The researchers conducted their study by comparing the genetic codes of working Wall Street traders to a control group of business students.

The researchers found evidence that genes affecting the way the brain processes dopamine, a chemical linked to risk-taking behavior, may be associated with success on Wall Street.

Traders who had successful careers, as measured by length of employment, tended to have genetic backgrounds linked to moderate levels of dopamine.

In other words, a good trader is likely to have a genetic code that influences a person's behavior toward competitiveness, but not the kind of thrill-seeking behavior in which risk taking becomes an addiction.

"Combining the personality analyses and genetic findings from the present study reveals that our sample of traders are analytical, integrative and can delay gratification," Zak and his co-authors wrote in their research paper.

The paper's title is "A Combination of Dopamine Genes Predicts Success in Professional Wall Street Traders." Zak co-authored the paper with two Claremont Graduate University students, Steve Sapra and Laura E. Bevin.

The researchers obtained their genetic samples by taking saliva samples from a test group of 60 Wall Street traders and a control group of 54 graduate students.

The implication of the study is not, Zak said, that hiring managers should take saliva samples from prospective traders and analyze applicants' genes before giving anyone a job on Wall Street.

Instead, he said the results suggest that Wall Street firms could do well to weed out both milquetoasts and cowboys from their applicant pool and favor candidates who balance competitiveness with a willingness to play by the rules.

The researchers also found that Wall Street could benefit from adding more women to the male-dominated trading industry.

"Nonprofessional female investors tend to be more risk-averse, trade less and earn higher returns," researchers wrote.

The study needs to be repeated with additional subjects to seek further confirmation of a link between genetics and trading careers, Zak said.

Zak is founding director of the Center for Neuroeconomics Studies at Claremont Graduate University, also holds a professorship in neurology at Loma Linda University. His research focuses on the role biological factors play in individuals' economic decisions.

Beyond the scope of his Wall Street study, Zak said his research indicates that business success and general prosperity are not the products of a Darwinian, dog-eat-dog struggle.

Instead, he finds that success can be linked the presence of oxytocin, a hormone linked to feelings of trust, within the body.

At a biological level, oxytocin may explain Adam Smith's observation that business owners seeking repeat business have an incentive to treat their customers' well.

"It makes us treat strangers like family," Zak said. "That's what trade does."

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