P1: ZBU Journal of Abnormal Child Psychology pp874-jacp-466277 April 24, 2003 22:26 Style file version May 30th, 2002 Journal of Abnormal Child Psychology, Vol. 31, No. 4, August 2003, pp. 457–470 ( C  2003) Callous-Unemotional Traits and Conduct Problems in the Prediction of Conduct Problem Severity, Aggression, and Self-Report of Delinquency Paul J. Frick, 1,3 Amy H. Cornell, 1 Christopher T. Barry, 2 S. Doug Bodin, 2 and Heather E. Dane 2 Received April 26, 2002; revision received July 22, 2002; accepted October 2, 2002 The role of callous-unemotional (CU) traits and conduct problems in predicting conduct problem severity, severity and type of aggression, and self-reported delinquency at a 1-year follow-up was investigated in a sample of 98 children (mean age 12.43; SD = 1.72) recruited from a community- wide screening. Children with both CU traits and conduct problems had a greater number and variety of conduct problems at follow-up than children who at the screening had high levels of conduct problems alone. However, this poorer outcome for children with CU traits could largely be accounted for by differences in initial level of conduct problem severity. Children with CU traits and conduct problems were also at risk for showing higher levels of aggression, especially proactive aggression, and self-reported delinquency. Importantly, these outcomes could not be solely explained by initial level of conduct problem severity. Finally, CU traits predicted self-reported delinquency in some children who did not initially show high levels of conduct problems and this predictive relationship seemed to be strongest for girls in the sample who were high on CU traits but who did not show significant conduct problems. KEY WORDS: callous-unemotional traits; aggression; delinquency; conduct problems. One major focus of research on childhood conduct problems has been to define potentially important sub- groups of children with conduct problems who differ on (a) the types and severity of conduct problems they dis- play, (b) the course and trajectory of their problem be- havior, and (c) theoretically important characteristics that could suggest different causal processes underlying their behavioral disturbance (see Frick & Ellis, 1999 for a re- view). Despite the general recognition that children with conduct problems represent a very heterogeneous group, few methods of subtyping have gained widespread accep- tance in research and practice. The one notable exception is the distinction made between youth with conduct prob- lems who differ on the age at which their serious antisocial 1 University of New Orleans, New Orleans, Louisianoa. 2 University of Alabama, Alabama. 3 Address all correspondence to Paul J. Frick, Department of Psychology, University of New Orleans, 2001 Geology & Psychology Building, New Orleans, Louisiana 70148; e-mail: pfrick@uno.edu. and aggressive behaviors begin to emerge (American Psy- chiatric Association, 2000). Specifically, there appears to be one group of chil- dren with conduct problems who begin showing severe problems prior to adolescence, usually as a continuation of behavior problems that start very early in development and steadily increase in rate and severity across childhood (Lahey & Loeber, 1994). In contrast, there is a second group of children whose severe conduct problems emerge with the onset of puberty without an earlier history of problem behavior (Hinshaw, Lahey, & Hart, 1993; Moffitt, 1993). Importantly, children with early onset conduct problems have proven to have poorer outcomes, such as being more likely to show antisocial and criminal behavior in adulthood, compared to their adolescent-onset counter- parts (Frick & Loney, 1999; Moffitt, 1993). In addition, children in the childhood-onset group are characterized by more aggression, more cognitive and neuropsychological disturbances, greater impulsivity, greater social alienation, 457 0091-0627/03/0800-0457/0 C  2003 Plenum Publishing Corporation