title: Heritable influences on behavioural problems from early childhood to mid-adolescence: evidence for genetic stability and innovation.
abstract: BACKGROUND
  Although behavioural problems (e.g., anxiety, conduct, hyperactivity, peer problems) are known to be heritable both in early childhood and in adolescence, limited work has examined prediction across these ages, and none using a genetically informative sample.
  
  
  METHODS
  We examined, first, whether parental ratings of behavioural problems (indexed by the Strengths and Difficulties questionnaire) at ages 4, 7, 9, 12, and 16 years were stable across these ages. Second, we examined the extent to which stability reflected genetic or environmental effects through multivariate quantitative genetic analysis on data from a large (n > 3000) population (UK) sample of monozygotic and dizygotic twins.
  
  
  RESULTS
  Behavioural problems in early childhood (age 4 years) showed significant associations with the corresponding behavioural problem at all subsequent ages. Moreover, stable genetic influences were observed across ages, indicating that biological bases underlying behavioural problems in adolescence are underpinned by genetic influences expressed as early as age 4 years. However, genetic and environmental innovations were also observed at each age.
  
  
  CONCLUSIONS
  These observations indicate that genetic factors are important for understanding stable individual differences in behavioural problems across childhood and adolescence, although novel genetic influences also facilitate change in such behaviours.
authors.affiliation: Department of Psychology,University of York,Heslington,York,UK.
authors.forename: G J
authors.initials: GJ
authors.lastname: Lewis
authors.affiliation: King's College London, MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry,Psychology & Neuroscience,De Crespigny Park,London,UK.
authors.forename: R
authors.initials: R
authors.lastname: Plomin
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology; D002648:Child; D002653:Child Behavior Disorders / Q000235:genetics* / Q000523:psychology; D002675:Child, Preschool; D004777:Environment; D005260:Female; D059647:Gene-Environment Interaction; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D015999:Multivariate Analysis; D010641:Phenotype; D000066553:Problem Behavior / Q000523:psychology; D011569:Psychiatric Status Rating Scales; D017678:Sex Distribution; D006113:United Kingdom
keywords: Behavioural problems; SDQ; genetics; longitudinal; twin study