In a recent post, James wrote about the Social Sensitivity hypothesis. Given findings that certain genetic variants will make a person more sensitive to social contact and more reliant on social contact under stress, it proposes that certain genetic variants ‘fit’ better with certain social structures. In support of this idea, Way and Lieberman (2010) find a correlation between the prevalence of this variant and the level of collectivism (as opposed to individualism) in a society.
An alternative explanation I’ve been thinking about is migration patterns. If genetic differences make a person less reliant on social networks, they may be more likely to migrate. This would predict that areas settled later in human history will have more ‘non socially sensitive’ individuals.