From ScienceDaily:
Appearing in the latest edition of The Journal of Politics published by Cambridge University Press, the research focused on 2,000 subjects from The National Longitudinal Study of Adolescent Health. By matching genetic information with maps of the subjects’ social networks, the researchers were able to show that people with a specific variant of the DRD4 gene were more likely to be liberal as adults, but only if they had an active social life in adolescence.
Dopamine is a neurotransmitter affecting brain processes that control movement, emotional response, and ability to experience pleasure and pain. Previous research has identified a connection between a variant of this gene and novelty-seeking behavior, and this behavior has previously been associated with personality traits related to political liberalism.
Lead researcher James H. Fowler of UC San Diego and his colleagues hypothesized that people with the novelty-seeking gene variant would be more interested in learning about their friends’ points of view. As a consequence, people with this genetic predisposition who have a greater-than-average number of friends would be exposed to a wider variety of social norms and lifestyles, which might make them more liberal than average. They reported that “it is the crucial interaction of two factors — the genetic predisposition and the environmental condition of having many friends in adolescence — that is associated with being more liberal.” The research team also showed that this held true independent of ethnicity, culture, sex or age.
I guess that means it’s not all a Marxist Plot. It also implies that conservatives have fewer friends in high school, but I’m not sure what would be the cause and what would be the effect in that case.
Read more here.

