Is political ideology something you’re born with? Scientists have uncovered a gene that predisposes people to be liberals—provided they had a lot of friends in high school. The study, conducted at UC San Diego and Harvard, matched 2,000 subjects’ genetic information with maps of their social networks, and found that a specific variant of the DRD4 dopamine receptor made subjects much more likely to lean left as adults—provided they were socially active teens, NBC reports.
“It is the crucial interaction of two factors—genetic predisposition and the environmental condition of having many friends in adolescence—that is associated with being more liberal,” the scientists wrote. The results were consistent regardless of the subject’s gender, age, ethnicity, or culture. (Read more genetics stories.)