Indonesian Adaptation of the Propensity to Morally Disengage Scale: A Rasch Analysis with Convergent Validity Evidence from the Dark Tetrad

The propensity to morally disengage is a cognitive mechanism through which individuals justify harmful behavior, yet no rigorously validated Indonesian measure has been developed using modern psychometric approaches. This study adapted a 16-item moral disengagement scale into Indonesian and evaluated its psychometric properties using Rasch measurement modeling, with convergent validity examined against four dark personality traits. A total of 603 Indonesian adults completed the adapted instrument. Initial analysis revealed that the original 7-point response format functioned suboptimally, and an empirically derived three-category structure was required to achieve ordered thresholds and optimal measurement properties. The final model demonstrated acceptable item fit, supported unidimensionality, minimal local item dependence, good reliability, and substantive measurement invariance across sex. Convergent validity was supported through positive correlations with all four dark personality dimensions, with the strongest associations observed for sadism and psychopathy. The adapted instrument provides a psychometrically defensible tool while underscoring the importance of empirically examining rating scale functioning in cross-cultural adaptation.