Validation of the Italian version of the Dark Tetrad at Work scale.

This study presents and validates the Italian adaptation of the Dark Tetrad at Work (DTW) scale, an instrument for assessing four socially aversive personality traits (narcissism, Machiavellianism, psychopathy and sadism) in the context of the workplace. A total of 300 Italian-speaking participants (50% female, M age = 32 years ± 9.2) and 253 English-speaking participants (38% female, M age = 39 years ± 12.1) were recruited via an online survey platform. The Italian-speaking sample was used to test the factorial structure, reliability and criterion-related validity of the Italian version of the DTW, whereas the English-speaking sample was used to test cross-language measurement invariance. Results from confirmatory factor analysis showed that the original four-factor model provided the best fit to the data. The Italian DTW scale demonstrated acceptable internal consistency, with reliability coefficients of ω = .77 for narcissism, ω = .80 for Machiavellianism, and ω = .81 for both psychopathy and sadism. Concurrent associations between the DTW scales and negative and positive workplace outcomes supported the criterion validity of the scale. Machiavellianism, psychopathy, and sadism positively correlated with counterproductive work behaviors and workplace bullying, and negatively with organizational citizenship behaviors and affective organizational commitment. In contrast, narcissism exhibited a unique pattern: It correlated positively with positive workplace behaviors and negatively with counterproductive behaviors toward the organization, but it was also found to be a significant predictor of workplace bullying. This finding may reflect multidimensional nature of narcissism, but a note of caution is warranted in interpreting this result, as all measurements relied on self-report instruments, introducing the possibility of socially desirable associations influencing the outcomes. Finally, the comparison with the English sample established configural, full metric and partial scale invariance, allowing for valid cross-language comparisons between Italian and English-speaking populations in the future. Preliminary Italian normative data were provided to offer a benchmark for the interpretation of DTW values. This study provides a reliable and valid instrument tailored to the Italian workforce, enhancing our understanding of dark personality traits within organizational contexts and providing organizations with an effective means to address and manage dark personality traits for a healthier workplace culture.