A bad apple may not spoil the barrel: Mechanisms of trust formation under misinformation exposure

Under widespread misinformation, deciding which news sources to trust is consequential. Here, we examine the mechanisms people use to form trust in news sources. Across 8 experiments, participants continuously evaluated a sequence of news posts that included one piece of misinformation. Then, they indicated trust in the source. For neutral content (Experiments 1-5), trust tracked the average reliability of the reports, whether the source was a news channel (Experiments 1-3) or an individual (Experiments 4-5). Despite clear detection of misinformation, there was no evidence for a “one strike and you’re out” mechanism. In contrast, for politically charged content (Experiments 6-7), Republicans continued to rely on averaging, whereas Democrats shifted to a mechanism that heavily penalized misinformation, differences that we discuss further. These findings suggest that, for neutral content, trust judgments follow equal-weighting strategy, but political priors can shape not only belief in specific reports, but the process of trusting news.