Cognition 166, 1–12 (2017)

Whether audiences perceive a communicator as credible is not based solely on perceived expertise, but also includes judgments of shared cultural beliefs and values. Accordingly, many hoped that the Pope's encyclical advancing the message that addressing climate change is a moral issue would resonate with US conservatives, who share the church's socially conservative values but tend to be more sceptical of climate change than liberals.

Asheley Landrum from Texas Tech University, USA, surveyed Americans before and after the release of the Pope's encyclical. Regression models showed that awareness of the Pope's encyclical increased beliefs about the seriousness of climate change and beliefs that climate change would have a greater effect on the poor, but only indirectly via increased perceptions of papal credibility. Moreover, this effect was moderated by political ideology, such that more conservative individuals were less likely to view the Pope as more credible, and were consequently less likely to show changes in beliefs. These results suggest that prominent figures cannot simply leverage their authority to influence public opinion on heavily politicized issues.