Belief in partisan news depends on favorable content more than on a trusted source

Surveys show that people trust news sources that support their political ideology, creating a feedback loop that sustains partisan disagreement about fact as well as opinion. However, most news sources do not publish sufficiently balanced content to disentangle the underlying dynamics: Do people believe partisan news because they trust the source or because the content favors their worldview? We experimentally isolated the effects of content and source on the credibility of partisan news. The results show that the credibility of partisan news depends on favorable content more than a trusted source. Unfavorable headlines were unlikely to be believed, but favorable headlines were readily believed even if attributed to mistrusted sources. When offered monetary incentives for correct evaluations, people were more likely to acknowledge the accuracy of unfavorable news. The findings suggest that interventions emphasizing accuracy may be more effective at mitigating alternative realities than efforts that promote source trust.