A recent paper suggests that there may be a genetic link between friends, that is, you may associate with others based on similar genetic patterns. The paper, published in the Proceedings of the National Academy of Sciences, found that even when controlling for genetic likeness due to sex, age, race or common ancestry, groups of friends had apparent genetic similarities at two genomic locations, one at a gene encoding the dopamine D2 receptor, DRD2, and the other at a cytochrome gene, CYP2A6. Whether this is a real genetic tendency is disputed in the genetics community. But this most recent news does highlight the almost weekly reports of genetic associations with various behaviors. While genetic associations with disease have better data, behavioral genetics is on less firm ground.