Diffusion of Complex Social Contagions: Network Structure and Critical Mass

About

Social contagions are ideas or behaviours that spread via social networks much like their biological counterparts. Recent work has identified two broad classes of social contagion: simple contagion (e.g. information) and complex contagion (e.g. rumours and social movements). Focusing on the latter, Vladimir Barash demonstrates how multiple exposures lead to the fragile nature of these contagions, the difficulty of predicting their diffusion extent and pathways, and their reliance on very different network structures than simple contagions to spread. With a set of new results that show the existence of a critical mass of adopters for any given complex contagion, Barash concludes that it is possible to predict the eventual number of adopters of any given rumour or social movement.