title: Drinking experience uncovers genetic influences on  alcohol expectancies across adolescence.
abstract: OBJECTIVE
  To test whether drinking onset moderates genetic and environmental contributions to individual differences in the etiology of alcohol expectancies across adolescence.
  
  
  METHODS
  Longitudinal twin design.
  
  
  METHODS
  Community sample from Los Angeles, CA, USA.
  
  
  METHODS
  A total of 1292 male and female twins, aged 11–18years, were assessed at 1 (n = 440), 2 (n = 587) or 3 (n = 265) occasions as part of the risk factors for the Antisocial Behavior Twin Study.
  
  
  METHODS
  Social behavioral (SB) alcohol expectancies were measured using an abbreviated version of the Social Behavioral subscale from the Alcohol Expectancy Questionnaire for adolescents (AEQ-A). Drinking onset was defined as >1 full drink of alcohol.
  
  
  RESULTS
  Alcohol expectancies increased over age and the increase became more rapid following onset of drinking. The importance of genetic and environmental influences on SB scores varied with age and drinking status, such that variation prior to drinking onset was attributed solely to environmental influences, whereas all post-onset variation was attributed to genetic influences. Results did not differ significantly by sex.
  
  
  CONCLUSIONS
  Only environmental factors explain beliefs about the social and behavioral consequences of alcohol use prior to drinking onset,whereas genetic factors explain an increasing proportion of the variance in these beliefs after drinking onset.
authors.affiliation: Division of Research, Kaiser Permanente Northern California, CA, USA. Kelly.c.young-wolff@kp.org
authors.forename: Kelly C
authors.initials: KC
authors.lastname: Young-Wolff
authors.forename: Pan
authors.initials: P
authors.lastname: Wang
authors.forename: Catherine
authors.initials: C
authors.lastname: Tuvblad
authors.forename: Laura A
authors.initials: LA
authors.lastname: Baker
authors.forename: Adrian
authors.initials: A
authors.lastname: Raine
authors.forename: Carol A
authors.initials: CA
authors.lastname: Prescott
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D000428:Alcohol Drinking / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology; D001290:Attitude; D002648:Child; D004777:Environment; D005260:Female; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D055361:Multilevel Analysis; D017711:Nonlinear Dynamics; D012307:Risk Factors; D012919:Social Behavior; D012931:Social Environment; D014429:Twins, Dizygotic / Q000235:genetics* / Q000523:psychology / Q000706:statistics & numerical data; D014430:Twins, Monozygotic / Q000235:genetics* / Q000523:psychology / Q000706:statistics & numerical data; D000066608:Underage Drinking / Q000523:psychology* / Q000706:statistics & numerical data