Although some studies include the antisocial dimension as a fourth dimension, the YPI assesses three dimensions: grandiose / manipulative (interpersonal), callous / unemotional (affective), and impulsive / irresponsible (behavioral)
psychopathic personality dimensions (Hare 1991).
Considering the relevance of the affective
dimension of the
psychopathic personality in developmental and predictive models of youth conduct problems, the Inventory of Callous - Unemotional traits (ICU) has been developed as a reliable and effective measure of callous — unemotional traits (CU) in childhood and adolescence.
It was hypothesized, based on the study of Andershed et al. (2001), that three groups of adolescents with a
psychopathic personality can be distinguished: 1) adolescents scoring low on the manipulative, unemotional, and irresponsible
dimension («relatively normal group»), 2) adolescents scoring moderately on the manipulative and unemotional
dimension and high on the irresponsible
dimension («impulsive, non-
psychopathic-like group»), and 3) adolescents scoring high on all three
dimensions («psychopathy - like group»).