In the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, a Limited Prosocial Emotions specifier was added to the conduct disorder diagnostic criteria to designate a subgroup of children who exhibit callous unemotional (CU) traits. The Inventory of Callous Unemotional Traits (ICU) is the only dedicated measure of CU traits and was influential in the development of the Limited Prosocial Emotions specifier. Despite its role in the research and diagnosis of CU traits, some questions have persisted regarding the internal consistency and validity of the ICU and its three subscales: callous, uncaring, and unemotional. Results of a meta-analysis revealed acceptable internal consistency and external validity for total ICU, callous, and uncaring scores, but not unemotional scores. These results support the utility of the total ICU, callous, and uncaring scales, but indicate weaknesses in the scale or construct of unemotionality as it relates to interpersonal callousness, uncaring, and antisociality.
Keywords: Inventory of Callous Unemotional Traits; Limited Prosocial Emotions; aggression; meta-analysis; psychopathy.