Commentary: Understanding social network analysis

In the linked study (doi:10.1136/bmj.a2338), Fowler and Christakis investigated the new and intriguing hypothesis that people’s happiness is influenced by, among other things, the happiness of their acquaintances, particularly first degree relatives, close friends, neighbours, and coworkers.1 The authors cleverly use the Framingham heart study’s existing database that includes, fortuitously rather than by design, information that can be used for social network analysis. Their results broadly confirm this hypothesis, but many readers will be unfamiliar with social network analysis, confused by the analytical techniques, and unsure about the validity of the findings. Humans are unavoidably social beings. Consequently, not only does society exist, but its existence is inevitable, and each person is influenced in many ways by society at large and individuals and groups within it. It follows that to understand the attributes of individuals (for instance their …