Time for an update: Belief updating on the basis of ambiguous scientific evidence
Mon-A7-Talk I-06
Presented by: Marcel R. Schreiner
Scientific evidence for many effects tends to be ambiguous. While the scientific community may be used to the ambiguity of study results, this may not be true for the general public, as suggested by, for example, public reactions to the “replication crisis”. We investigated how people update their preexisting beliefs about psychological effects based on ambiguous scientific evidence. Specifically, we investigated influences of subjective expertise, trust in psychological science, and the number of studies investigating an effect, as well as systematic strategies of belief updating. In an online experiment (N = 297), we presented participants a series of fictitious psychological hypotheses. For each hypothesis, they first had to rate their preexisting belief about the validity of the effect and their subjective expertise on the topic. Participants were then presented a series of fictitious study outcomes, some of them finding confirmatory and some finding contradictory evidence. Finally, they were asked to rate their posterior belief. Controlling for scientific literacy and education, we found a negative effect of subjective expertise and positive effects of trust in psychological science and number of studies on belief updating. We did not find evidence for systematic belief updating except for a strategy according to which participants weight the outcome of the most recent study stronger than that of previous studies. The results advance our understanding of how people adjust their beliefs based on scientific evidence and provide practical implications for science communication.
Keywords: belief updating, science communication, metascience, advice taking, statistical modeling