Title: A Psychological Vaccine Against Fake News by Sander van der Linden (University of Cambridge) Are we living in a post-truth society? What is the current status of “facts” and “expertise”? In this talk, I will discuss recent psychological theorizing around fake news, attitude polarization, motivated cognition, and misinformation. I’ll start by presenting a series of experimental studies (N > 6,000) examining the crucial role of expert consensus in how people form judgments about contested societal issues across the ideological spectrum. I will illustrate that such perceptual judgments are easily distorted by misinformation, which can spread much like a viral contagion. By combining data from the lab and the field, I’ll then demonstrate that it is possible to inoculate (“vaccinate”) people against fake news. I’ll end the talk by showcasing a popular online social impact game we developed and evaluated (N= 15,000)—with governments and social media companies—to help citizens around the world recognize and resist unwanted attempts to influence and mislead.