title: The genetic etiology of inhibitory control and behavior problems at 24 months of age.
abstract: BACKGROUND
  To investigate links between inhibitory control (IC) and behavior problems in early childhood, as well as genetic and environmental covariances between these two constructs.
  
  
  METHODS
  Parent and laboratory ratings of IC and parent ratings of externalizing and attention deficit hyperactivity disorder behaviors were administered at 24 months of age on a sample of 291 same-sex twin pairs (131 monozygotic, 160 dizygotic).
  
  
  RESULTS
  There were significant phenotypic associations between both IC assessments and the two areas of behavioral maladjustment (correlations ranged from -.13 to -.57). Multivariate analyses revealed that phenotypic covariance between IC and behavior problems could be substantially explained by common genetic influences (genetic correlations ranged from -.30 to -.74). Parent ratings of IC showed higher phenotypic and genetic correlations with behavior problems than lab ratings of IC.
  
  
  CONCLUSIONS
  This study is the first to examine the etiology of the covariance between IC and related behavioral difficulties in toddlerhood. Findings suggest that low levels of IC can be considered a genetic risk factor for the development of early emerging behavior problems.
authors.affiliation: Department of Psychology, University of Wisconsin-Madison, Madison, WI 53706-1611, USA. jgagne@wisc.edu
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Gagne
authors.forename: Kimberly J
authors.initials: KJ
authors.lastname: Saudino
authors.forename: Philip
authors.initials: P
authors.lastname: Asherson
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000235:genetics* / Q000523:psychology*; D002652:Child Behavior / Q000523:psychology; D002653:Child Behavior Disorders / Q000235:genetics* / Q000523:psychology*; D002675:Child, Preschool; D005260:Female; D005824:Genetics, Behavioral / Q000379:methods; D006801:Humans; D007175:Impulsive Behavior / Q000235:genetics / Q000523:psychology; D007266:Inhibition, Psychological; D007389:Internal-External Control; D008297:Male; D010290:Parents; D012307:Risk Factors; D012931:Social Environment; D013694:Temperament