Abstract
BACKGROUND: The dark triad concept suggests dark personality traits share a common core. Having reliable measurement tools is essential to test this claim. Concerns exist about the widely used Dark Triad Dirty Dozen (DTDD) tool, specifically regarding its ability to fully assess psychopathy. This study aims to adapt the DTDD for a Czech population and to enhance the psychopathy subscale by adding items. Examining the scale's functioning in different linguistic and cultural contexts is crucial for ensuring its validity beyond the populations in which it was originally developed, and the Czech sample provides an opportunity to assess the stability of the DTDD in a less frequently studied setting. METHODS: This study (n = 6715, Mean Age = 36.14, SD = 14.72, Females: 65.5%) collected data from four online surveys in a Czech population. In addition to socio-demographic characteristics, we measured empathy, the Dark Triad (Machiavellianism, narcissism, psychopathy), self-esteem, Agreeableness, Conscientiousness and Neuroticism. RESULTS: Results supported the original 12-item DTDD's three-factor structure (CFI = 0.942; TLI = 0.925; RMSEA = 0.062; SRMR = 0.055), showing good internal consistency for the general Dark Triad factor (Cronbach's α = 0.85 and McDonald's ω = 0.89). A 14-item DTDD version with additional items demonstrated slightly lower fit (CFI = 0.93; TLI = 0.912; RMSEA = 0.063; SRMR = 0.062) and comparable internal consistency to the 12-item version. The 12-item version was invariant between genders, with males scoring higher. Narcissism correlated negatively with Agreeableness, Conscientiousness, and self-esteem, and positively with Neuroticism. Machiavellianism and psychopathy were negatively associated with empathy, Agreeableness, and Conscientiousness, and positively with Neuroticism. CONCLUSIONS: This research confirms the 12-item DTDD scale's validity in the Czech population.