Genetics meets social networks! In a paper today in PNAS Fowler et al compare the topological characteristics of the social networks of MZ and DZ twins and find that some network properties are heritable. This is expanding on some previous work that showed that the −G1438A polymorphism within the promoter region of the 5-HT2A serotonin receptor gene is associated with variation in popularity. The results are interesting, that among teenagers in a various scools, that the number of times a person is named as a friend is heritable (more similar for MZ twins than DZ twins). Adding to this there were another handful of features that were heritable. Overall, this topic is pretty thought provoking, i wonder how many parents would line up for a drug to increase popularity!