Development and tests of short versions of the Youth Psychopathic traits Inventory and the Youth Psychopathic traits Inventory-Child Version

The adolescent Youth Psychopathic Traits Inventory (YPI) and its child version (YPI-CV) are sound but lengthy instruments for measuring psychopathic traits in youths. The current study develops psychometrically strong short versions of these instruments. Samples used for item reduction were community samples of adolescents (n = 2105, age 16-19, 49% boys) and children (n = 360, age 9-12, 52% boys). Stepwise parallel reduction using principal components analyses and content-related arguments resulted in two highly similar short instruments of 18 items each. In both versions, near identical and theoretically comprehensible three factor structures were demonstrated, which were crossvalidated in independent samples (CFI = .97 and .97; RMSEA = .044 and .038, respectively). Results were similar for boys and girls. The short instruments were reliable (Cronbach's αs of .85 and .83) and covered all core characteristics of the psychopathic personality construct. The short versions showed a high convergence with the original long instruments (r = .95 and .93, respectively) and similar correlations to external criterion measures of conduct problems. Therefore, the abbreviated versions are practical and valid alternatives for the original YPIs when administration time is limited. © 2010 Hogrefe & Huber Publishers.