Dr. Ruud Custers (Utrecht University)

Abstract

Accurate knowledge about the outcomes of one’s actions is a prerequisite for successful goal-directed behavior. Like many animals, humans can learn such action-outcome relations through trial and error. However, our species also has the unique ability to communicate any learned action-outcome relation to others. In today’s world, these communicated beliefs about action outcomes travel at an unprecedented and ever-increasing rate through various media including the internet. We rarely visit a restaurant without being exposed to reviews, comments and “likes” and increasingly rely on strangers’ opinions for even more important choices such as medical treatments, or financial decisions. While this sharing of acquired knowledge should be beneficial for society as a whole, there may also be detrimental consequences as the veracity of action-outcome beliefs people hold is not always evident: Some people are convinced that alternative medicines are curing their cancer, or that interacting with people from a certain ethnic background will have negative consequences. How can such potentially erroneous action-outcome beliefs persist even if they do not accurately reflect relations in the real world? I will present a line of studies in which we demonstrate that people test the validity of beliefs they receive from others, and that random fluctuations or incidental patterns that are perceived in experienced evidence that seemingly confirm the communicated belief can cause erroneous beliefs to be consolidated.