A massive new study that included data from more than a million people suggests that genetics may nudge some individuals toward more risky behavior like smoking, drinking, and speeding.
Conducted by an international team of scientists led by researchers from the Social Science Genetic Association Consortium (SSGAC), the study published today in the journal Nature Genetics identified 124 genetic variants associated with a person’s willingness to take risks. The study looked at a person’s propensity for “risky behaviors” like smoking, drinking, driving fast, and having multiple sexual partners.
“Risk tolerance is a fundamental parameter in the behavioral sciences and has been widely studied in social science genetics,” said Jonathan Beauchamp of the SSGAC, a lead researcher on this paper and an assistant professor at the University of Toronto. “But until now few genetic variants had been robustly linked to risk tolerance. The study is an effort to get a fuller picture of the genetic factors involved and is a first step towards understanding how those factors interact with environmental factors to influence risk-taking.”
The Role of Genetics
While the focus of the new research looks at genetic influence, the researchers note that environmental, cultural and demographic circumstances play a much more significant role in a person’s tolerance for risk. However, the study illustrates that genetics has a small but important role. The genetic variants identified account for just a fraction of the difference in risk tolerance observed between groups of people. By using a “poly genetic” score the researchers were able to capture the combined effect of a million genetic variants to reach an estimate showing that genetics accounts for about 1.6 percent of the variation in risk tolerance across individuals.
The genetic associations point to the role of genes that regulate neurotransmitters such as glutamate and GABA — which are chemical messengers that both stimulate and calm the brain.
This study is significant on many levels. For one, risk tolerance is among the most intensively studied traits in social science, because it plays a role in predicting economic and social outcomes as well as personality measures. This study may also contribute to the debate around whether having a risk tolerance in one area, say a willingness to bungee jump, corresponds with taking a risk in another realm, like taking a risk financially. The researchers found evidence of shared genetic influences across risk tolerance and risky behaviors.
“Genetic variants associated with more risk tolerance tend to also be associated with more speeding, drinking, smoking, and cannabis consumption, and with riskier investments and sexual behavior,” Beauchamp said.
The study is also significant for its size. It dwarfs past genetic research on risk tolerance and risky behavior that relied on data from perhaps a few hundred or a few thousand individuals. In this work, the researchers look at data from more than a million people including data from about 500,000 23andMe customers who consented to participate in research, and an almost equally large set of data from the UK Biobank. The researchers then replicated their findings using data from about ten other small studies. The massive sample size for this study — orders of magnitude larger than previous genetic studies on risk tolerance — allowed researchers to see associations they were not able to see before.
“The study illustrates the power of big data and the potential of the research model pioneered by 23andMe,” said David Hinds, Ph.D., a research fellow and statistical geneticist at 23andMe. “AT the same time it is important to point out that these results do not explain much of the variation in risk tolerance. More work is needed.”
23andMe data has helped this same group of researchers, the Social Science Genetic Association Genetic Consortium, to complete a series of similarly large studies into such things as educational attainment, depression and subjective well-being.