Social influence network theory presents a mathematical formalization of the social process of attitude changes that unfolds in a social network of interpersonal influences. This book brings the theory to bear on lines of research in the domain of small group dynamics concerned with changes of group members' positions on an issue, including the formation of consensus and of settled disagreement, via endogenous interpersonal influences, in which group members are responding to the displayed positions of the members of the group. Social influence network theory advances a dynamic social cognition mechanism, in which individuals are weighing and combining their own and others' positions on an issue in the revision of their own positions. The influence network construct of the theory is the social structure of the endogenous interpersonal influences that are involved in this mechanism. With this theory, the authors seek to lay the foundation for a better formal integration of classical and current lines of work on small groups in psychological and sociological social psychology.

“Social Influence Network Theory pivots on a process model of attitude formation and change that accords pride of place to interpersonal influences mediated by social connections. Friedkin and Johnsen bring contemporary social network theory to bear on fundamental and long-standing puzzles about group process and functioning, including consensus formation, polarization, factionalization, and decision making. Their book – a potent and welcome contribution to social network science – both demands and gives serious attention to how and why ‘network effects’ operate, on individuals and groups alike.” – Peter V. Marsden, Harvard University

“This book provides an elegant formal model of the social influence process among people in groups and social networks and shows how this model can be used to illuminate and integrate basic processes in group dynamics such as social comparison, majority/minority influence, group polarization, and the effects of status structures. Social scientists have long acknowledged that the social influence process is central to the ways that individuals think and act and social structures emerge. This book shows how we can systemize our understanding of this core social process and gain a powerful analytic purchase on the ways that people make groups and groups make people. It is a must read for serious students of group dynamics, especially mathematically oriented ones.” – Cecilia L. Ridgeway, Lucie Stern Professor, Stanford University

“Summarizing their thoughts over many years, Noah Friedkin and Eugene Johnsen have written a book that will influence the way people think about influence in small groups for years to come.” – Peter Bearman, Columbia University