Elizabeth J. Marsh


Professor of Psychology and Neuroscience and Associate Chair, Department of Psychology & Neuroscience, Duke University

Elizabeth J. Marsh Webpage

ABSTRACT | Populist Beliefs: Byproducts of an Adaptive System? 

A wall along the US-Mexico border. Tariffs on Chinese goods. The resurrection of the coal industry. These policies appeal to many people even though little evidence supports them, and it is difficult to change people’s beliefs about them. As a cognitive psychologist, I see the problem filtered through the lens of what we know about the construction, representation, and updating of knowledge more generally. Humans learn, maintain, and update an impressive amount of information, reflecting a cognitively efficient system adapted to these goals – but the same processes that support accurate knowledge can also lead to acceptance of unsupported infromation. For example, we have an impressive ability to handle garbled messages, understanding disfluent speech and ambiguous referents, drawing inferences to fill in the gaps and interpreting information based on what we already know and believe.  But this tolerance for messy communications means that we sometimes miss errors in the incoming stream of information, even when we know better. Anchoring on the larger literature on knowledge provides a starting point for solutions; for example, consider the human bias to believe that incoming information is true. This regularity led us to predict that corrections would be more likely to stick when they induced belief than when they refuted beliefs. Overall, my argument is that the basic science of knowledge provides a useful starting point for thinking about people’s acceptance vs. rejections of populist ideas.