Westerwick, A., Sude, D.J., Robinson, M., & Knobloch-Westerwick, S. (in press, 2020). Peers versus pros: Confirmation bias in selective exposure to user-generated versus professional media messages and its consequences. Mass Communication and Society. https://www.tandfonline.com/doi/full/10.1080/15205436.2020.1721542
Political information is now commonly consumed embedded in user-generated content and social media. Hence, peer users (as opposed to professional journalists) have become frequently encountered sources of such information. This experiment tested competing hypotheses on whether exposure to attitude-consistent versus -discrepant political messages (confirmation bias) depends on association with peer versus professional sources, through observational data and multi-level modeling. Results showed the confirmation bias was differentiated, as attitude importance fostered it only in the peer sources condition: When consuming user-generated posts on political issues, users showed a greater confirmation bias the more importance they attached to a specific political issue. Furthermore, exposure generally affected attitudes in line with message stance, as attitude-consistent exposure reinforced attitudes, while attitude-discrepant exposure weakened them (still detectable a day after exposure). Attitude impacts were mediated by opinion climate perceptions.