Online-endorsed misinformation about climate change: examining the relationship between heuristic cues of perceived expertise, messages style and bandwagon to assess message credibility and sharing intentions

When seeking climate change-related information online, social media users often rely on various heuristic cues to assess the credibility of the content. This study applied the Heuristic-Systematic Model (HSM) to examine the intertwined role of three heuristic cues – perceived expertise, message style, and bandwagon effect – in influencing users’ evaluation of online-endorsed misinformation about climate change. Using a 2 (perceived expertise: absent vs. present) × 2 (MS: long vs. short) × 2 (bandwagon: strong vs. weak) between-subjects factorial design (N = 320), the study revealed significant two-way interactions: perceived expertise and MS influenced both perceived credibility and sharing intention. Similarly, perceived expertise and bandwagon significantly affected sharing intention, while bandwagon and MS impacted perceived credibility. A moderated-moderated mediation analysis was conducted to explore the combined effects of heuristic cues on sharing intention, mediated by perceived credibility. The results indicated that the bandwagon cue’s effect on sharing intention, mediated through perceived credibility, was conditional on short messages but not on professional expertise (PE) cues. These findings provide robust evidence that sharing intentions can persist even when credibility perceptions are low, offering new insights into the complex relationship between heuristic cues that commonly coexist on social media platforms. Theoretical and practical implications are discussed.