Australasian Mathematical Psychology Conference 2019

Why do echo chambers form? The role of trust, population heterogeneity, and objective truth

Amy Perfors
Melbourne School of Psychological Sciences, University of Melbourne
Danielle Navarro
University of New South Wales

Many real-world situations involve learning entirely or mostly based on the information provided by other people, which creates a thorny epistemological problem: how does one determine which of those people to trust? Previous work has shown that even populations of rational Bayesian agents, faced with this problem, polarise into “echo chambers” characterised by different beliefs and low levels of between-group trust. In this study we show that this general result holds even when the reasoners have a more complex meaning space and can communicate about their beliefs in a more nuanced way. However, even a tiny amount of exposure to a mutually trusted “ground truth” is sufficient to eliminate polarisation. Societal and psychological implications are discussed.