Objective Prior emergency risk communication incidents create enduring psychological legacies that complicate the interplay between health-promoting and health-risk tendencies. This study investigates how negative and positive legacies jointly operate within this spillover effect. Specifically, we examine whether positive legacies can offset the adverse effects of negative ones and identify the boundary conditions moderated by emerging versus recurring epidemics—under which this buffering mechanism fails. Methods Grounded in the Stress Spillover Model and Post-traumatic Growth Theory, a dual-path parallel mediation model for PERCI was constructed. Adopting a cross-sectional survey combined with scenario simulation to capture cross-epidemic effects, we recruited 822 participants who have experienced COVID-19 via convenience and snowball sampling. Data were examined using structural equation modeling. Results PERCI exerts significant spillover effects via an asymmetric dual-path mechanism. While parallel mediation by both positive and negative legacies was confirmed, a crucial asymmetry emerged: the negative pathway substantially dominated the positive one, indicating that risk impulses often override promotional resources. However, boundary condition analysis revealed a divergent regulation: in recurring epidemics, positive legacies significantly strengthened the promotion pathway ( β = 0.14, p 0.05), effectively offsetting negative inertia. Conversely, in emerging epidemics, negative legacies reinforced the risk pathway ( β = 0.15, p 0.05), creating scenarios where risk behaviors remain largely unchallenged by positive resources. Conclusion While negative legacies exert a dominant risk effect, positive legacies provide an independent protective pathway that partially offsets this inertia, but only under specific boundary conditions. These findings highlight a critical, non-linear interplay in cross-epidemic responses. Public health interventions must adopt a context-specific dual strategy: simultaneously mitigating negative legacies and strengthening positive ones. Crucially, standard promotional tactics may fail to counteract dominant risk pathways during emerging outbreaks, necessitating tailored communication strategies that account for the asymmetric nature of psychological legacies.
Wu et al. (Fri,) studied this question.