Culture, not just genes, can drive evolutionary outcomes, according to a study  that compares individualist and group-oriented societies across the globe.The study looks at the interplay across 29 countries of two sets of data, one genetic and the other cultural.It was found that most people in countries widely described as collectivist have a specific mutation within a gene regulating the transport of serotonin, a neurochemical known to profoundly affect mood.

In China and other east Asian nations,  up to 80 percent of the population carry this so-called “short” allele, or variant, of a stretch of DNA known as 5-HTTLPR.Earlier research has shown the S allele to be strongly linked with a range of negative emotions, including anxiety and depression.It is also associated with the impulse to stay out of harm’s way.By contrast, in countries of European origin that prize self-expression and the pursuit of individual over group goals, the long or “L” allele dominates, with only 40 percent of people carrying the “S” variant.Ancient cultures in Asia, Africa and Latin America highly exposed to deadly pathogens, they conjecture, may have tended toward collectivist norms in order to better combat disease.That social transformation, in turn, could have favored the gradual dominance of the risk-avoidance S allele.

The study, published in Britain’s Proceedings of the Royal Society , offers a novel explanation as to how this divergence might have come about.
Setting aside discredited ideas linking genetics and race, the researchers suggest that culture and genes may have interacted over time to shape the process of natural selection, helping individuals — and the societies in which they lived — to survive and thrive.

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