title: Delinquent peer affiliation as an etiological moderator of childhood delinquency.
abstract: BACKGROUND
  Prior research has indicated that affiliation with delinquent peers activates genetic influences on delinquency during adolescence. However, because other studies have indicated that the socializing effects of delinquent peers vary dramatically across childhood and adolescence, it is unclear whether delinquent peer affiliation (DPA) also moderates genetic influences on delinquency during childhood. Method The current study sought to evaluate whether and how DPA moderated the etiology of delinquency in a sample of 726 child twins from the Michigan State University Twin Registry (MSUTR).
  
  
  RESULTS
  The results robustly supported etiological moderation of childhood delinquency by DPA. However, this effect was observed for shared environmental, rather than genetic, influences. Shared environmental influences on delinquency were found to be several-fold larger in those with higher levels of DPA as compared to those with lower levels. This pattern of results persisted even when controlling for the overlap between delinquency and DPA.
  
  
  CONCLUSIONS
  Our findings bolster prior work in suggesting that, during childhood, the association between DPA and delinquency is largely (although not solely) attributable to the effects of socialization as compared to selection. They also suggest that the process of etiological moderation is not specific to genetic influences. Latent environmental influences are also amenable to moderation by measured environmental factors.
authors.affiliation: Department of Psychology, Michigan State University, East Lansing, MI 48824, USA. burts@msu.edu
authors.forename: S A
authors.initials: SA
authors.lastname: Burt
authors.forename: K L
authors.initials: KL
authors.lastname: Klump
mesh_terms: D002648:Child; D002653:Child Behavior Disorders / Q000235:genetics*; D005260:Female; D059647:Gene-Environment Interaction; D020022:Genetic Predisposition to Disease; D006801:Humans; D007604:Juvenile Delinquency; D008297:Male; D010379:Peer Group; D012931:Social Environment; D012951:Socialization; D014427:Twins / Q000235:genetics* / Q000523:psychology; D014429:Twins, Dizygotic / Q000235:genetics / Q000523:psychology; D014430:Twins, Monozygotic / Q000235:genetics / Q000523:psychology