Community Detection as a Method to Control For Homophily in Social Networks

People tend to be very similar to their friends. Groups of friends often have similar political affiliations, exercise habits, and socioeconomic backgrounds. Is this similarity because people become friends and then start influencing each other, or because their friendship begins due to similar traits? If one person starts exhibiting similar behavior as their friend, is it because their friend caused them to behave that way or because their similar traits have caused them both to start exhibiting the trait? This question is difficult to answer, but researchers investigating how people interact with each other often encounter the issue. In this paper I put forth a method to help differentiate between one friend influencing another (contagion) and two friends behaving similarly because the cause of the behavior is the same reason they became friends in the first place (homophily).