Odds are that gambling's a genetic trait, study shows

The next time you lose a bet, you may be able to blame your genes. Researchers in Singapore and the US have linked five genes to people's behaviour when it comes to betting.

The genes are all involved in regulating dopamine, a chemical released in the brain that signals pleasure and motivates people to seek rewards. The scientists said their work shows how people have hard-wired biases when they think about strategies and make decisions.

"If you think of the brain as a computing machine, there are areas that take inputs, crank them through an algorithm and translate them into behavioural outputs," said Assistant Professor Ming Hsu from the University of California, Berkeley.

The researchers used MRI imaging to study the brains of about 220 Han Chinese students at the National University of Singapore (NUS) while they bet against an anonymous competitor via a computer.

An almost complete genetic profile of each student was compiled in a database as part of a larger project involving over 3,000 students to look into human decision-making.

"We know from brain imaging studies that when people compete against one another, they actually engage in two distinct types of learning processes," said graduate student Eric Set from the University of Illinois at Urbana-Champaign.

The study found that variations in three genes determined how well students were better able to imagine what their competitors were thinking and respond accordingly - a process known as "belief learning".

Differences in the other two genes affected how quickly the students forgot past experiences and changed strategies - called trial-and-error "reinforcement learning".

Professor Chew Soo Hong from NUS' Department of Economics said the study's findings show how the different dopamine genes contribute to an individual's thinking in a "winner-takes-all competitive game" which emulates the workings of a patent race.

"In grouping people's responses using genetic differences, our neurogenetic approach offers a powerful strategy to unravel the neurochemical networks underpinning human decision making," said Professor Richard Ebstein of NUS' Department of Psychology.

The hard-wired biases could have an impact on business decisions, the researchers said.

Their work was published on Monday in the online edition of the US Proceedings of the National Academy of Sciences.

zengkun@sph.com.sg

This article was first published on June 18, 2014.
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