Inhibiting Informal Social Control: How Callous–Unemotional Traits and Body Shame Impede Bystander Intervention in Cyber Delinquency

Bystander intervention acts as a critical mechanism of informal social control against cyber delinquency. Grounded in Social Information Processing theory, this study examines the barriers impeding students from acting as capable guardians. Analysis of 423 university students supported a serial mediation model: Callous–unemotional (CU) traits inhibit intervention by eroding perceived social support, subsequently desensitizing individuals to harm severity. Crucially, body shame functioned as a distinct moderator, attenuating the link between harm perception and helping behavior. These findings suggest inaction stems from both emotional detachment and social identity threats. Consequently, prevention efforts should incorporate social support and emotion-regulation strategies to promote bystander intervention in response to cyber delinquency.