Lots of things that we normally think of as part of our environment, like being bullied, being in the school band, or how many friends we have, turn out to have a genetic basis (Vinkhuyzen et al). Lauren Brent and colleagues have shown that the same is true for rhesus macaques: aspects of an individual’s social network (such as whether they are friends with individuals who are not friends), are highly heritable.
The study also looked at selection on aspects of sociality and found effects from the interaction between serotonergic genes (controlling for genetic background and family and other environmental factors). A nice aspect of this study is that they repeated the genetic analysis on randomly generated social networks and found the derived social metrics had zero heritability, so the results are not somehow an artefact of the data.
- Brent, L. J. N., Heilbronner, S. R., Horvath, J. E., Gonzalez-Martinez, J., Ruiz-Lambides, A., Robinson, A. G., et al. (2013). Genetic origins of social networks in rhesus macaques. Scientific Reports, 3
- Vinkhuyzen, A. A. E., Boomsma, D. I., & Posthuma, D. (2010). Genetic influences on “environmental” factors. Genes, Brain and Behavior, 9, 276–287.