Combined genetic information and brain scans from more than 25,000 people suggest a common genetic and neurobiological basis for risky behavior.
Better understanding what motivates risk-taking could help mitigate its costs to society.
University of Zurich neuro-economists Gökhan Aydogan, Todd Hare, Christian Ruff, and others looked at the genetic characteristics that correlate with risk-taking behavior. Using a representative sample of 25,000 people, the researchers examined the relationship between individual differences in brain anatomy and the propensity to engage in risky behavior.
“We found both functional and anatomical differences,” says Aydogan.
Specific characteristics were found in several areas of the brain:
- In the hypothalamus, where the release of hormones (such as orexin, oxytocin, and dopamine) controls the vegetative functions of the body;
- in the hippocampus, which is essential for storing memories;
- in the dorsolateral prefrontal cortex, which plays an important role in self-control and cognitive deliberation;
- in the amygdala, which controls, among other things, the emotional reaction to danger;
- and in the ventral striatum, which is activated when processing rewards.
The researchers were surprised by the measurable anatomical differences they discovered in the cerebellum, an area that is not usually included in studies of risk behaviors on the assumption that it is mainly involved in fine motor functions. In recent years, however, significant doubts have been raised about this hypothesis—doubts that the new results back up.
“It appears that the cerebellum does after all play an important role in decision-making processes such as risk-taking behavior,” confirms Aydogan. “In the brains of more risk-tolerant individuals, we found less gray matter in these areas. How this gray matter affects behavior, however, still needs to be studied further.”
The study is the first time that the foundations of risk-taking behavior have been investigated with such a large and representative sample. It is also the first study to examine possible influencing factors—genetic predisposition and differences in anatomy and function of brain areas—in combination rather than in isolation.
At present, it is still unclear to what extent the connection between genetic disposition and neurobiological expression is causal, stresses Aydogan: “How exactly the interplay of environment and genes determines risk-taking requires further research.”
The study appears in the journal Nature Human Behavior.
Source: University of Zurich