Biology of Social Interactions

A full understanding of social networks must take biology into account. We explore both the biology of individuals that plays a role in social network phenomena (including genetics, epigenetics, physiology, and neurobiology), and the genetic and evolutionary processes shaping networks in our species (and in other social species) as a whole. We consider both how our biology can shape our social interactions and how our social interactions can affect our biology.

We are exploring why our tendency to form networks with particular topological architectures may ultimately exist. We are approaching this question from a number of angles. For example, we have examined the heritability of social network features, and the genetic similarity of friends, and we have conducted field research on the features and functions of social networks cross-culturally, including in an “evolutionarily relevant” populations living in our ancestral environment in Africa. We have also done work developing mathematical models for the evolution of social networks and related phenomena, such as cooperation, homophily, and in-group favoritism. Related work in the lab explores such topics as the role of violence and antagonistic interactions in network formation and the origins and consequences of homogamy and active choice of romantic partners.

Ongoing work in the lab explores the physiological correlates of various social network positions and social behaviors.  A substantial line of work is evaluating the role of social interactions in the microbiome — how commensal microbes might use our networks as highways to be traversed, creating evolutionary niches within our social fabric.  Finally, we have a new line of work on human chemosignaling, addressing the issue of how humans elaborate and sense volatile organic compounds, and thus the role of odor and olfaction in human social relationships.