Social Media Misinformation Wars: How Message Features, Political Cynicism, and Conspiracy Beliefs Shape Government-Led Public Health Debunking Effectiveness

This study investigates the effectiveness of public health institutions’ misinformation debunking on social media by examining the impact of message features—social media intermediaries, message framing, and social cues—alongside the moderating roles of political cynicism and conspiracy beliefs. We conducted preregistered survey experiments in Hong Kong, the Netherlands, and the United States (total N = 2,769). Results show that sponsored messages outperformed AI recommendations. Causal framing would backfire for the cynics (in both Hong Kong and the Netherlands). In the United States, peer-shared messages enhanced source and message evaluations among those with higher conspiracy beliefs.