title: Psychopathic personality traits: heritability and genetic overlap with internalizing and externalizing psychopathology.
abstract: BACKGROUND
  Little research has examined genetic and environmental contributions to psychopathic personality traits. Additionally, no studies have examined etiological connections between psychopathic traits and the broad psychopathological domains of internalizing (mood and anxiety) and externalizing (antisocial behavior, substance abuse). The current study was designed to fill these gaps in the literature.
  
  
  METHODS
  Participants were 626 pairs of 17-year-old male and female twins from the community. Psychopathic traits were indexed using scores on the Multidimensional Personality Questionnaire (MPQ). Symptoms of internalizing and externalizing psychopathology were obtained via structured clinical interviews. Structural equation modeling was used to estimate genetic and environmental influences on psychopathic personality traits as well as the degree of genetic overlap between these traits and composites of internalizing and externalizing.
  
  
  RESULTS
  Twin analyses revealed significant genetic influence on distinct psychopathic traits (Fearless Dominance and Impulsive Antisociality). Moreover, Fearless Dominance was associated with reduced genetic risk for internalizing psychopathology, and Impulsive Antisociality was associated with increased genetic risk for externalizing psychopathology.
  
  
  CONCLUSIONS
  These results indicate that different psychopathic traits as measured by the MPQ show distinct genetically based relations with broad dimensions of DSM psychopathology.
authors.affiliation: Department of Psychology, University of Minnesota, Twin Cities Campus, Minneapolis, MN 55455-0344, USA. bloni001@umn.edu
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Blonigen
authors.forename: Brian M
authors.initials: BM
authors.lastname: Hicks
authors.forename: Robert F
authors.initials: RF
authors.lastname: Krueger
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Patrick
authors.forename: William G
authors.initials: WG
authors.lastname: Iacono
mesh_terms: D000293:Adolescent; D000987:Antisocial Personality Disorder / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology*; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000175:diagnosis / Q000235:genetics / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D010641:Phenotype; D012931:Social Environment; D011795:Surveys and Questionnaires; D014427:Twins / Q000235:genetics*