title: The amplification of risk in experimental diffusion chains.
abstract: Understanding how people form and revise their perception of risk is central to designing efficient risk communication methods, eliciting risk awareness, and avoiding unnecessary anxiety among the public. However, public responses to hazardous events such as climate change, contagious outbreaks, and terrorist threats are complex and difficult-to-anticipate phenomena. Although many psychological factors influencing risk perception have been identified in the past, it remains unclear how perceptions of risk change when propagated from one person to another and what impact the repeated social transmission of perceived risk has at the population scale. Here, we study the social dynamics of risk perception by analyzing how messages detailing the benefits and harms of a controversial antibacterial agent undergo change when passed from one person to the next in 10-subject experimental diffusion chains. Our analyses show that when messages are propagated through the diffusion chains, they tend to become shorter, gradually inaccurate, and increasingly dissimilar between chains. In contrast, the perception of risk is propagated with higher fidelity due to participants manipulating messages to fit their preconceptions, thereby influencing the judgments of subsequent participants. Computer simulations implementing this simple influence mechanism show that small judgment biases tend to become more extreme, even when the injected message contradicts preconceived risk judgments. Our results provide quantitative insights into the social amplification of risk perception, and can help policy makers better anticipate and manage the public response to emerging threats.
authors.affiliation: Center for Adaptive Rationality, Center for Adaptive Behavior and Cognition, and mehdi.moussaid@gmail.com.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Moussaïd
authors.affiliation: Center for Adaptive Behavior and Cognition, and.
authors.forename: Henry
authors.initials: H
authors.lastname: Brighton
authors.affiliation: Center for Adaptive Behavior and Cognition, and Harding Center for Risk Literacy, Max Planck Institute for Human Development, 14195 Berlin, Germany; and Department of Psychology, Social Psychology and Decision Sciences, University of Konstanz, 78457 Konstanz, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Gaissmaier
mesh_terms: D000465:Algorithms; D000891:Anti-Infective Agents, Local / Q000009:adverse effects / Q000494:pharmacology; D003198:Computer Simulation; D004059:Diffusion of Innovation; D006801:Humans; D033181:Information Dissemination / Q000379:methods*; D008960:Models, Psychological; D017063:Outcome Assessment, Health Care; D010465:Perception; D018570:Risk Assessment; D012307:Risk Factors; D014260:Triclosan / Q000009:adverse effects / Q000494:pharmacology
chemical_list: D000891:Anti-Infective Agents, Local; D014260:Triclosan
keywords: collective behavior; diffusion chains; opinion dynamics; risk perception; social transmission