Why Do People Share Vaccine Misinformation on Social Media? A Psychological and Social Analysis

Abstract

Background: Misinformation sharing on social media is a global concern with varying influencing factors across different societies. Understanding these factors is crucial to designing effective interventions, particularly in non-Western contexts such as Iran. Methods: This cross-sectional quantitative study used a crowdsourcing survey with chain referral sampling to recruit 600 adult media users in Hamadan, Iran. (57.8% women, 42.2% men). A structured questionnaire adapted from validated scales assessed psychological, social, and cognitive factors. Partial least squares structural equation modeling (PLS-SEM) was applied to analyze data with significance set at p < 0.05. Results: Key predictors of sharing intention included trust in government (β = 0.147, p < 0.001), accuracy assessment (β = -0.539, p < 0.001), fear of missing out (β = 0.110, p = 0.003), media dependency (β = 0.080, p = 0.023), social comparison (β = -0.089, p = 0.006), and media fatigue (β = -0.124, p = 0.001). Media literacy did not moderate these relationships. Among demographic variables, only education level showed a significant effect (β = -0.12, p < 0.01). The structural equation modeling results indicated good model fit: χ² = 112.5, SRMR = 0.07 (values <0.08 suggest good fit), and NFI = 0.90 (values >0.90 are acceptable). Conclusion: Our study reveals unique cultural drivers of health misinformation sharing in Iran, highlighting the critical roles of institutional trust and accuracy assessment. The findings emphasize the need for context-specific strategies in developing interventions to combat misinformation.

Keywords: Health Information, Misleading, Social Media, COVID-19 Vaccines, Developing Countries