Adult friend search
We linked these genetic data with social network information from the original school-based surveys along with information about personal characteristics and social environments accumulated across Add Health follow-up waves.
Analyses focus on a group of genetically homogeneous respondents identified as being of ancestral European origin (. In step 1, we test whether friends are more genetically similar to one another than to randomly selected peers.
We also observe apparent social–genetic effects in which polygenic scores of an individual’s friends and schoolmates predict the individual’s own educational attainment.
As part of the survey, students were asked to list the names of their friends.