Cognitive ability and psychopathic traits: independent and interactive associations with youth conduct problems.

Although average or high IQ was central to initial conceptualizations of psychopathy, IQ is typically negatively associated with oppositional defiant disorder (ODD) and conduct disorder (CD). Few studies have simultaneously considered narcissism and callous-unemotional (CU) traits with respect to ODD and CD symptoms, including potential interactive associations with IQ. Participants were 221 ethnically-diverse (45 % non-White) 6-9 year-old children with (n = 114) and without (n = 107) attention-deficit/hyperactivity disorder (ADHD) with separate parent and teacher ratings of narcissism, CU traits, ODD, and CD. To minimize shared method variance, we conservatively examined the association of parent-rated psychopathic traits with teacher-rated ODD and CD as well as the association of teacher-rated psychopathic traits with parent-rated ODD and CD. Controlling for age, sex, and the number of child ADHD symptoms, narcissism, but not CU traits, uniquely and positively predicted parent- and teacher-rated ODD and CD symptoms. We also observed a significant IQ × narcissism interaction where narcissism was more strongly associated with ODD and CD among children with high IQ relative to average and low IQ youth. Whereas studies of youth psychopathic traits focus almost exclusively on CU traits, narcissism independently predicted separate parent and teacher ratings of ODD and CD, particularly among children with high IQ. These preliminary data persuasively suggest that early narcissism is a critical facet of psychopathy and in conjunction with IQ, may suggest a unique profile associated with emergent conduct problems.