Contagious Interactions Essays on social and epidemiological networks

This dissertation has two overall aims; to explore and develop the use of SNA in sociology, and to show that sociology has much to give to other sciences. Interdisciplinary collaboration is necessary because we do not live in a world in which subject areas are strictly isolated. Human beings are social animals, and a sociological understanding is crucial in all human-related science. The examination in this thesis of different kinds of social networks and how they affect lives of individuals (and vice versa) will provide knowledge both in the development of methods for analyzing social networks, and in their specific scientific areas. Paper I-IV investigates sexual networks and how the characteristics of the network as well as individual behaviors affect the spread of sexually transmitted infections (STIs). The fifth and last paper focuses on how individuals who committed suicide in Stockholm during the 1990s where connected to each other in families and at workplaces, and how the exposure to someone's suicide affects the individual's risk of committing suicide.