Share If You Believe, Comment If You Doubt: The Effect of Source of Information, Trust, and Belief in Conspiracy Theories on Engagement with Facebook Posts.

This study examines the effect of one of three sources of information: a politician (authority figure), a physician (expert), and an ordinary person (non-expert) who appeared in a personal story related to a controversial issue (COVID-19 vaccination) on Facebook, on the willingness to engage with it. Using a between-subjects experiment (N = 848) conducted among Israeli adults (18 and older), we found a higher likelihood of sharing the story in interpersonal conversations than in other types of communications, regardless of the source that appeared in the story. However, respondents with high levels of institutional trust preferred sharing a politician's story, while conspiracy believers tended to comment on an ordinary person's story. The findings of the different patterns of communication behavior among conspiracy believers and people with high trust in political institutes contribute to our understanding of the mechanisms underlying the spread of misinformation in the digital age and during times of crisis.