Unrelated people who are more similar genetically tend to have more similar attitudes and preferences, reports a new Cornell study published May 7 in the Proceedings of the National Academy of Sciences. The findings suggest that genetic data -- taken as a whole -- could eventually help predict economic and political preferences.
The research team, led by Daniel Benjamin, Cornell assistant professor of economics, studied 3,000 people with comprehensive genetic data and information on economic and political preferences. "We showed that on the whole the genes help explain preferences by showing that people who share more of their genome have more similar preferences, but we were unable to connect specific genes with specific preferences," said Benjamin.
Thus, the researchers concluded current genetic data has essentially no predictive power for the 10 traits studied, which included preferences about environmental policy, foreign affairs, financial risk and economic fairness.
This conclusion is at odds with dozens of previous papers that have reported genetic associations with such traits, which Benjamin concludes may be partly because of their small sample size; his study included 10 times more participants than the previous studies.
"If you want to find genetic variants that account for some of the differences between people in their economic and political behavior, you need samples an order of magnitude larger than those presently used," he said.
He added, "an implication of our findings is that most published associations of genes with political and economic outcomes are probably false positives. These studies are implicitly based on the incorrect assumption that there are common genetic variants with large effects."
The study also found evidence that the effects of individual genetic variants are tiny, and these variants are scattered across the genome. The research team concluded that it may be more productive in future research to focus on behaviors that are more closely linked to specific biological systems, such as nicotine addiction, obesity and emotional reactivity, and are, therefore, likely to have stronger associations with specific genetic variants.