Online Social Influence and Traffic-Related Interpersonal Violence: The Conditional Effect of Prior Social Exposure on Aggressive Communication.

Social media consumption can transmit normative cues that shape health behaviors, yet how different types of normative information on social media jointly influence perceived norms and behavioral intentions remains underexplored. This experimental study (N = 500) examined the separate and combined effects of descriptive and injunctive norm cues embedded in social media videos and comments on perceived norms and intentions to use aggressive communication in traffic-related interpersonal violence, which is a growing global health concern. We then examined prior social exposure as a boundary condition. When both norm types were present, injunctive cues exerted a stronger influence on normative perceptions. Structural equation modeling revealed an indirect effect of exposure on intentions mediated by injunctive norms, but only among participants with low and moderate prior social exposure. Findings suggest the need to consider the interplay of multiple types of normative information and heterogeneity in susceptibility in social norm research and norm-based health communication interventions.