Online deviant behavior is a series of maladaptive behaviors that may have adverse effects on the physical and mental health of others and adolescents in the Internet environment. Previous studies have paid more attention to the risk factors of adolescent online deviant behavior. However, its protective factors and psychological mechanisms remain unclear. Thus, this study explored the protective effect of virtuous personality trait on adolescents’ online deviant behavior and its psychological mechanism. A total of 851 Chinese college students anonymously completed a series of questionnaires about virtuous personality trait, moral disengagement, perspective taking, and online deviant behavior. The findings showed the following: (1) Virtuous personality trait was negatively correlated with online deviant behavior. (2) Moral disengagement mediated the relationship between virtuous personality trait and online deviant behavior. (3) Perspective taking moderated the first half stage of the mediation model in which college students’ virtuous personality trait influences online deviant behavior via moral disengagement. (4) A moderated moderated-mediation analysis found that gender moderated the moderating effect of perspective taking on the relationship between virtuous personality trait and moral disengagement. This study is helpful to demonstrate the protective effect and psychological mechanism of virtuous personality trait on online deviant behavior. Some theoretical and practical significance and limitations were also analyzed and discussed.

Moral disengagement (MD) typically peaks during adolescence. While the Dark Triad (DT) traits—Machiavellianism, psychopathy, and narcissism—are broadly linked to MD, the specific prospective pathways through which individual DT components predict distinct MD strategies remain unclear, particularly with respect to gender-specific variations in these influences among adolescents. To systematically investigate these temporal associations, this study employed Cross-Lagged Panel Network (CLPN) modeling on a sample of 1410 Chinese adolescents (M_age = 16.95, SD = 0.75) surveyed across three waves at three-month intervals. Results revealed a hierarchical pattern of DT influence: Machiavellianism exerted the strongest predictive effect on the MD system, followed by psychopathy, while narcissism showed negligible or even negative effects. Among MD strategies, euphemistic labelling, advantageous comparison and displacement of responsibility were the most responsive to DT traits. Bridge centrality analysis confirmed Machiavellianism as the primary cross-domain connector linking DT traits to MD. Weak but significant reciprocal effects were observed: MD slightly fed back onto later Machiavellianism and psychopathy, supporting a partially bidirectional process. Gender-separated networks revealed divergent pathways: Machiavellianism served as the key DT-MD bridge for males, whereas psychopathy fulfilled this role for females. These findings refine the understanding of the “dark side” of moral development by highlighting mechanism-specific MD vulnerabilities and demonstrating that the primary socio-cognitive pathway to MD is gender-contingent, thereby advancing developmental models of MD.