Assessment of the Dark Triad in the Prison Population: A Meta-Analysis of Reliability Generalization

This paper explores the reliability of assessment instruments used in the prison population to measure the Dark Triad, a constellation of personality traits including machiavellianism, narcissism, and psychopathy. A systematic literature review was conducted using six databases, and 12 articles were selected according to the eligibility criteria. A Cronbach’s alpha reliability generalization meta-analysis was carried out, which reported acceptable internal consistencies (≥ .70) for all three subscales, with machiavellianism achieving the best estimated alpha, and good internal consistency (≥ .80) for the Dirty Dozen, the most commonly used scale in this context. However, the paucity of studies, publication bias, and high heterogeneity reflected in Cochran’s Q statistic and I2 index (≥ 75%) compromise the generalizability of the estimates and underline the need to examine the which moderating variables that influence this variability.