The spread of alcohol consumption behavior in a large social network

Background—Alcohol consumption has important health related consequences and numerous biological and social determinants. Objective—Quantitatively explore the possibility of person-to-person spread of alcohol consumption behavior within a large social network involving friends, co-workers, siblings, spouses, and neighbors followed for 32 years. Design—Longitudinal network cohort study Setting—The Framingham Heart Study. Participants—12,067 people assessed at several time points between 1971 and 2003. Measurements—At each time point, we measured: (1) self-reported alcohol consumption behavior, both in terms of number of drinks per week on average over the past year as well as number of days drinking within the past week, and (2) social network ties. Results—Discernible clusters of drinkers and abstainers were present in the network at all time points, and the clusters extended to three degrees of separation (e.g., to a person's friends ’ friends’ friends). These clusters were not solely due to selective formation of social ties among drinkers