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Watching participants in slopestyle and half-pipe skiing, snowboarding, flipping, curling, cartwheeling and otherwise contorting themselves in the air during the Winter Olympics competition in Sochi, many of us have probably wondered not only how the athletes managed to perform such feats but also why. Helpfully, a recent study of the genetics of risk-taking intimates that their behaviour may be motivated, at least in part, by their DNA.
For some time, scientists and many parents have suspected that certain children are born needing greater physical stimulation than others, suggesting that sensation seeking, as this urge is known in psychological terms, has a genetic component. A thought-provoking 2006 study of twins, for instance, concluded that risk-taking behaviour was shared by the pairs to a much greater extent than could be accounted for solely by environmental factors. If one twin sought out risks, the other was likely to do so as well.
But finding which genes or, more specifically, which tiny snippets of DNA within genes, might be influencing the desire to huck oneself off of a snow-covered slope has proven to be troublesome. In recent years, scientists zeroed in on various sections of genes that affect the brain's levels of response to the neurotransmitter dopamine, a substance that is known to influence our feelings of pleasure, reward and gratification. People who engage in and enjoy extreme, daredevil conduct, researchers presumed, would likely process dopamine differently than those of us content to watch.
But the results of some early genetic studies comparing dopamine-related portions of genes with sensation seeking were inconsistent. Some found that people with certain variations within genes, including a gene called DRD4 that is believed to be closely involved in the development and function of dopamine receptors in our brain, gravitated toward risky behavior. Others, though, found no such links. But most of these studies focused on so-called deviant risk-taking, such as gambling and drug addiction.
Cynthia Thomson, then a graduate student in the exercise physiology department at the University of British Columbia, wondered whether these past studies might have been looking at the wrong activities, and if it wouldn't be more telling to examine risk-seeking in sports like skiing and snowboarding that allow for a broad range of styles, from sedate and cautious (my approach) to hurtling and occasionally being airborne.
To find out, she first developed a questionnaire specifically related to on-slope behaviour, which asked questions about how often, fast and recklessly someone schussed or rode. Did they leap from cliffs? Or did they stick to blue, intermediate runs?
Then she visited several of the large resorts dotting British Columbia and approached patrons between the ages of 17 and 49, asking them to fill out questionnaires, as well as a second, standard personality questionnaire. A high combined score on these tests would indicate a strong tendency to embrace risks. The volunteers also gave a cheek swab for DNA typing.
Returning to her lab, she began quantifying variations within the volunteers' DRD4 genes. Focusing on a single, tiny section of the gene, she found that skiers and riders who harboured a particular variant of DNA coding were much more likely to score high on the tests of risk-taking.
Because the number of volunteers in this experiment was small, only 117 men and women, Thomson, who is now a teaching fellow at Quest University Canada, went back to the mountains and recruited an additional 386 participants.
And again, in this expanded group, she found the same association between the variation of the DRD4 gene and a willingness to take risks on the slopes. The variant's overall effect was slight, explaining only about 3 per cent of the difference in behavior between risk takers and the risk averse, but was statistically significant and remained intact, even when Thomson and her colleagues controlled for gender and sport expertise.
In essence, the findings suggest that some people might have an innate, inherited need to turn to risky activities to reach "their optimal level of arousal," Thomson says, even if their parents are quiet, respectable types. (The DNA from each parent can contain different portions of the variant, Thomson says, which can combine in the child to create a slopestyle medalist.)
Given no healthy outlets for their sensation seeking, such individuals might turn to more problematic behaviours, like gambling or drugs, says Thomson, emphasising that this idea is speculative and that no single, isolated aspect of our genetics will ever fully explain why we act as we do. But if you have a 4-year-old who performs back flips off the couch, she says, you might "consider directing him or her to freestyle skiing or gymnastics classes," rather than, say, curling.
©2014 The New York Times
