LAUSR

The Dark Triad is a term used to describe a constellation of three socially undesirable personality traits: psychopathy, narcissism, and Machiavellianism. The aim of the present study was to examine the psychometric properties of the Dirty Dozen scale, a brief measure of the Dark Triad, among a sample of 412 at-risk youths from Portugal ( M  = 13.19 years; SD  = 1.41; age range = 12–17 years), composed of male ( n  = 200; M  = 13.32 years; SD  = 1.41 years) and female youths ( n  = 212; M  = 13.08 years; SD  = 1.41 years). As expected, our translation had a three-factor structure that was invariant across the sexes. Adequate psychometric properties were demonstrated in terms of internal consistency (i.e., Cronbach’s alpha and Omega coefficient), convergent validity (i.e., with measures of self-reported delinquency, and sensation seeking), discriminant validity (i.e., with measures of self-esteem, and self-control), criterion-related validity (i.e., with drug use, and risky sex), and know-groups validity (boys versus girls). We also found that sex differences in self-reported delinquency were partially mediated by sex differences in the Dark Triad traits. Our findings suggest the Dirty Dozen is a valid and useful measure in the study of at-risk for delinquency adolescents.