Rumors are a powerful, pervasive, and persistent force affecting people and groups. They play an important role in a variety of human attitudes and actions, yet we know little about how they propagate over time and in the context of the complex social networks that exist in our world. Like infectious diseases, many rumors engender mistrust, suspicion, and conflict between people groups; such rumors "survive"-even thrive-and are believed as fact despite well-meaning attempts to dispel them. How does this happen? That is, what are the mechanisms involved in rumor propagation over time and across social spaces? This project will address that question in a couple of new ways, using a dynamical systems framework, and in the context of an unusual collaboration between mathematicians and psychologists. First, rumor selection (choosing whether or not to share a particular rumor) and belief in that rumor will be computationally modeled using insights and data gained from empirical research and using a dynamic framework that accounts for different ways in which social networks are configured. Second, a series of laboratory experiments will be conducted in which groups of networked participants will select and discuss rumors via email. Both the mathematical modeling and the computer assisted laboratory experiments will investigate how social space (how a person's social network is configured) and network homogeneity (the extent of same group membership in a network) affect group-level rumor outcomes over time. Finally, an exploratory arm of the study will pilot a web-site for collection of field data related to propagation mechanisms and will search for archival repositories of rumor. In summary, the project will study how social space configuration and network homogeneity affect temporal and spatial patterns of rumor selection and belief, resulting in a dynamical understanding of rumor activity and increased knowledge about how motivational processes associated with group membership affect rumor activity over time and space (e.g., how desiring to build up one's self or one's ingroup may lead to the popularity of and belief in rumors derogating a different group). Such knowledge is vital for the effective prevention of and response to harmful rumors, especially those that foster intergroup distrust, discord, and hostility.
