The current study used model-based cluster analyses to determine if there are two distinct variants of adolescents (ages 11 - 18) high on callous-unemotional (CU) traits that differ on their level of anxiety and history of trauma. The sample (n = 272) consisted of clinic-referred youths who were primarily African-American (90%) and from low income families. Consistent with hypotheses, three clusters emerged, including a group low on CU traits, as well as two groups high on CU traits that differed in their level of anxiety and past trauma. Consistent with past research on incarcerated adults and adolescents, the group high on anxiety (i.e., secondary variant) was more likely to have histories of abuse and had higher levels of impulsivity, externalizing behaviors, aggression, and behavioral activation. In contrast, the group low on anxiety (i.e., primary variant) scored lower on a measure of behavioral inhibition. On measures of impulsivity and externalizing behavior, the higher scores for the secondary cluster only were found for self-report measures, not on parent-report measures. Youths in the primary cluster also were perceived as less credible reporters than youth in the secondary or cluster low on CU traits. These reporter and credibility differences suggest that adolescents within the primary variant may underreport their level of behavioral disturbance, which has important assessment implications
