The Influence of Motivation on Evidence Assimilation in a Controlled Judgement Task

Prior research suggests that people ignore evidence that is inconsistent with what they want to believe. However, this research on motivated reasoning has focused on how people reason about familiar topics and in situations where the evidence presented interacts with strongly-held prior beliefs (e.g., the effectiveness of the death penalty as a crime deterrent). This makes it difficult to objectively assess how biased people are in motivated-reasoning contexts. Indeed, recent work by Jern and colleagues (2014) suggests that apparent instances of motivated reasoning may actually be instances of rational belief-updating. Inspired by this new account, the current studies reexamined motivated reasoning using a controlled categorization task and tested whether people assimilate evidence differently when they are motivated to maintain a certain belief versus when they are not. Contrary to earlier research on motivated reasoning, six studies with children and adults (N = 1295) suggest that participants’ motivations did not affect their information search and their beliefs were driven primarily by the evidence, even when the evidence was incongruent with their motivations. This work provides initial evidence for the account proposed by Jern and colleagues.