Loading...
Ever wonder how “birds of a feather flock together” and “opposites attract” both seem to be true? To examine this issue, researchers examined data from the large National Longitudinal Study of Adolescent Health (Add Health). Participants were genotyped and provided names of up to 10 friends at three different time points over 6 years.
Networks of unrelated friends were mapped by similarity of alleles (homophily) or relative absence of allelic similarity (heterophily). The six genes of interest were DRD2, DRD4, CYP2A6, MAOA, SLC6A3 (dopamine transporter), and SLC6A4 (serotonin receptor). In analyses controlled for age, sex, and population stratification (geography), DRD2 alleles were associated with homophily; people with the same allele were…