Psychological Medicine

Original Articles

Psychopathic personality in children: genetic and environmental contributions

S. Bezdjiana1 c1, A. Rainea2, L. A. Bakera1 and D. R. Lynama3

a1 Department of Psychology, University of Southern California, Los Angeles, CA, USA

a2 Departments of Criminology, Psychiatry, and Psychology, University of Pennsylvania, Philadelphia, PA, USA

a3 Department of Psychology, Purdue University, West Lafayette, IN, USA


Background The current study investigates whether the underlying factor structure of psychopathic personality traits found in adults is similar to that in children and what the extent of the genetic and environmental influences are on these psychopathic traits.

Method Psychopathic personality traits were assessed in a community sample of 1219 twins and triplets (age 9–10 years) through caregiver reports of each child's behavior using the Child Psychopathy Scale (CPS).

Results Confirmatory factor analyses revealed an optimal two-factor solution (callous/disinhibited and manipulative/deceitful) to the CPS subscales. Bivariate genetic modeling of the two computed factor scores revealed significant genetic as well as unique environmental influences on psychopathic personality traits in both boys and girls, with heritability estimates of 0.64 and 0.46, respectively, in boys and 0.49 and 0.58, respectively, in girls. No shared environmental influences on psychopathic personality traits were found.

Conclusions The relationship between the two factors was mediated by both genetic and unique environmental factors common to both traits.

(Received July 20 2009)

(Revised March 23 2010)

(Accepted March 31 2010)

(Online publication May 20 2010)


c1 Address for correspondence: Dr S. Bezdjian, University of Southern California, Department of Psychology (SGM 501), Los Angeles, CA 90089-1061, USA. (Email: