Abstract. We tested the psychometric properties of the Dark Triad Dirty Dozen measure of psychopathy, narcissism, and Machiavellianism in Portugal (n = 1,034) and Spain (n = 386). Adult (M = 43.40, SD = 14.81, range = 18–88) participants (1,113 women) completed the Dirty Dozen measure of each trait along with ultrabrief measures of extraversion, openness, neuroticism, agreeableness, conscientiousness, and religiousness and a lengthier measure of individual differences in depression, anxiety, and stress. Using confirmatory factor analysis and multigroup confirmatory factor analysis, we found evidence for measurement invariance for a 3-factor model of the Dirty Dozen in the sexes and countries. The Dark Triad traits and disagreeableness were present across the traits and countries. Across depression, anxiety, and stress, correlations with the Dark Triad traits were stronger in men than women. Our results suggest that the scale translations – in each country – are trustworthy paving the way for inter-Iberian and international collaborations.
