Generating a Mediation Model of Moral Cost and Aggression

The effects of moral protective factors (e.g., moral cost) on aggression and the underlying mechanisms remain unclear. To address this issue, this study developed the Moral Cost of Aggression Questionnaire (MCAQ) and validated its psychometric properties in 516 college students (287 female; <i>M</i>age = 19.77 years, <i>SD</i> = 1.61). Subsequently, the relationships among moral cost, positive outcome expectancies for aggression (POEA), and aggression were examined in 749 college students (330 females; <i>M</i>age = 18.96 years, <i>SD</i> = 0.74). Mediation analysis indicated that POEA mediated the relationship between moral cost and aggression. This pattern of associations is consistent with the hypothesis that moral cost is negatively associated with aggression, in part through its link to lower subjective value of aggressive outcomes (i.e., lower POEA). This study provides a reliable and valid measure of the trait moral cost (MCAQ) and offers preliminary empirical support for a discounting mechanism in which moral cost is associated with reduced aggression via decreased POEA. These findings suggest that interventions targeting both moral cost and outcome valuation may be a useful direction for future research.