Fear appeals amplify the continued influence effect of health wish rumor: Mediation of perceived efficacy

The spread of health wish rumors (misinformation promising unverified solutions to health threats) poses significant risks to public health decision-making. By integrating rumor typology and the Extended Parallel Process Model (EPPM), this study investigates how fear appeals amplify the Continued Influence Effect (CIE) of health wish rumors and their behavioral consequences. Through two experiments (N = 180), we demonstrate that health wish rumors under fear appeals sustain reliance on corrected falsehoods and increase purchase intentions by leveraging perceived efficacy. Experiment 1 (N = 54 undergraduates) employed a within-subjects design to compare inference scores and purchase intentions among three conditions: fear appeal misinformation correction, general appeal misinformation correction, and no-misinformation control. Linear mixed models revealed fear appeal misinformation corrections yielded significantly higher inference scores (b = 0.96, p < 0.001) and purchase intentions (b = 0.73, p < 0.001) than no-misinformation controls. Experiment 2 (N = 126 diverse adults) replicated these effects and identified perceived efficacy as the critical mediator (CIE: partial mediation, ab = 0.24, 95% CI [0.05, 0.46]; purchase intentions: full mediation, ab = 0.26, 95% CI [0.06, 0.51]), whereas perceived threat showed no mediating role. These findings challenge static rumor typology assumptions by showing that fear contexts override the reputed correctability of health wish rumors. This work reveals how health wish rumors can exploit the persuasiveness of fear appeal by inflating perceived efficacy. It also provides actionable insights for combating real-world health rumors, demonstrating that debunking efforts should prioritize reducing efficacy beliefs about health wish rumors.