Scientists have been searching for a genetic explanation for athletic ability for decades. So far their efforts have focused largely on genes related to physical attributes, such as muscular function and aerobic efficiency. But geneticists have also started to investigate the neurologicalbasis behind what makes someone excel in sports—and new findings implicate dopamine, a neurotransmitter responsible for the feelings of reward and pleasure. Dopamine is also involved in a host of other mental functions, including the ability to deal with stress and endure pain. Consequently, the new research supports the idea that the mental—not just the physical—is what sets elite athletes above the rest.
In an effort to piece together what makes a great athlete great, researchers at the University of Parma in Italy collected DNA from 50 elite athletes (ones who had achieved top scores at an Olympic Games or other international competition) and 100 nonprofessional athletes (ones who played sports regularly, but below competitive level). They then compared four genes across the two groups that had previously been suggested as linked to athletic ability: one related to muscle development, one involved with transporting dopamine in the brain, another that regulates levels of cerebral serotonin and one involved in breaking down neurotransmitters.
The researchers found a significant genetic difference between the two groups in only one of the genes: the one involved in transporting dopamine. Two particular variants of this gene (called the dopamine active transporter, or DAT) were significantly more common among the elite athletes than in the control group. One variant was almost five times more prevalent in the elite group (occurring in 24 percent of the elites versus 5 percent of the rest); the other variant was approximately 1.7 times more prevalent (51 percent versus 30 percent). The results were published in Journal of Biosciences.
The idea that dopamine could play a role in mediating athletic ability makes sense, given previous research on the neurotransmitter and DAT in particular, says John Salamone, a professor of psychology at the University of Connecticut who was not involved in the research. “Animal studies show that the DAT gene is involved with increased motor activity, energy expenditure and reward-seeking behavior,” he explains. “So it’s plausible that variants of the DAT gene could be related to aspects of athletic performance.”
Similarly, two studies conducted in 2012 found evidence that genes related to dopamine were associated with increased levels of “risk-seeking” behavior in groups of several hundred skiers and snowboarders. Such behavior could make the difference in which athletes grab the gold, says Cynthia Thomson, a geneticist and sports psychologist at University of the Fraser Valley in British Columbia, who led the studies. “To reach the podium an athlete has to take risks, whether by attempting a more difficult skill to obtain more points or by veering on the edge of control to attain greater speeds,” she says. “Our results suggest that variations in the brain’s dopamine pathway can affect a person’s propensity to take such risks, which could therefore make them more likely to reach elite levels in sport.”
Nevertheless, more research will be needed to verify the connection between dopamine and athletic ability—and more still to test whether it is a cause and effect relationship. The dopamine transporter is also behind several disorders such as depression, attention deficit hyperactivity disorder (ADHD), bipolar disorder and Parkinson’s disease.