In a study of some 25,000 people, researchers at the University of Zurich have found that genes and brain anatomy influence whether someone is a risk-taker.

There is widespread evidence that people can be predisposed to take risks. However, there has been less research into how a genetic disposition translates into risky behavior. The only research to date that looked at structural brain-imaging data has come from small, nonrepresentative samples of just a few hundred people.

An international team led by neuro-economists at UZH studied the genetic information and brain scans of more than 25,000 people to understand how genetic characteristics correlate with risk-taking behavior such as drinking, smoking, driving and sexual promiscuity.

The large sample allowed the researchers to control for several variables such as age, gender and other factors to reveal that there is a link between brain function and anatomy and risky behavior.

The study, which was published in Nature Human BehaviorExternal link last week, confirmed some of the areas of the brain that are expected to be associated with risky behavior. This includes the hypothalamus, where hormones such as dopamine are released, and the prefrontal cortex, which plays an important role in self-control and cognitive deliberation.

The more surprising finding through was the area of the brain called the cerebellum, which is not usually included in studies on risk behavior because it is mainly involved in fine motor function. The UZH study found that cerebellum in fact plays an important role in decisions about risk-taking behavior.

“In the brains of more risk-tolerant individuals, we found less gray matter in these areas. How this gray matter affects behaviour, however, still needs to be studied further,” noted Gökhan Aydogan, who was one of the co-authors of the study.

This is the first time that genetic predisposition and differences in brain anatomy have been investigated together in connection with risk-taking behavior in such a large and representative sample.