ABSTRACT
This chapter is an overview of the two network mechanisms-socialization and social comparison-that lie beneath the popular metaphors about contagion. I have two goals for the chapter: distinguish the two mechanisms by the network conditions in which they occur, and describe how the mechanisms combine in a predictable way as they generate contagion. Neither mechanism is the whole story; at the same time, neither is completely wrong. Socialization turns out to describe the occasional, critical instance of opinion and behavior brokered between groups. Social comparison describes the more frequent instance of interpersonal influence within groups and indifference beyond the group. The only course of action that is clearly wrong is to ignore either one of the two mechanismsand that is a course too often taken. I begin with introductions to the network mechanisms and the early research in which they were conceptualized and follow that with summary evidence on the way they combine in the actual diffusion of opinion and behavior, which connects back to the
two-step flow of information discovered long ago in the influential stream of marketing research from Columbia University’s Bureau for Applied Social Research and connects forward to social capital applications of network theory in contemporary research on competitive advantage. Given the role of this chapter in this book, I put aside network analyses of buyerseller relations (e.g., DiMaggio & Louch, 1998; Frenzen & Davis, 1990) to focus on the way networks create contagion among potential buyers. Furthermore, to focus on the network mechanisms, I put aside significant differences between contagions such as the risk they pose (e.g., Van den Bulte & Lilien, 2001) or their complexity (e.g., Centola & Macy, 2007). Finally, I focus on contagion at the person-to-person level because that is where the social psychology of the network mechanisms is most intuitive. I hasten to note that such a focus comes at the cost of putting aside most studies of contagion between organizations, which are some of the most sophisticated empirical studies available (see Strang & Soule, 1998, for a review; see also Davis, Morrill, Rao, & Soule, 2008).
