title: Explaining individual differences in alcohol intake in adults: evidence for genetic and cultural transmission?
abstract: OBJECTIVE
  The current study aimed to describe what proportion of variation in adult alcohol intake is attributable to genetic differences among individuals and what proportion to differences in environmental experiences individuals have been exposed to. Effects of age, gender, spousal resemblance, and cultural transmission of alcohol intake from parents to offspring were taken into account.
  
  
  METHODS
  In a twin-family design, the effects of genetic and cultural transmission and shared and nonshared environment on alcohol intake were estimated with genetic structural equation models. Data originated from adult twins, their siblings, parents (n = 12,587), and spouses (n = 429) registered with the population-based Netherlands Twin Register (63.5% female; ages 18-97 years).
  
  
  RESULTS
  Alcohol intake (grams per day) was higher among men than women and increased with age. Broad-sense heritability estimates were similar across sex and age (53%). Spousal resemblance was observed (r = .39) but did not significantly affect the heritability estimates. No effects of cultural transmission were detected. In total, 23% of the variation in alcohol intake was explained by additive genetic effects, 30% by dominant (nonadditive) gene action, and 47% by environmental effects that were not shared among family members.
  
  
  CONCLUSIONS
  Individual differences in adult alcohol intake are explained by genetic and individual-specific environmental effects. The same genes are expressed in males and females and in younger and older participants. A substantial part of the heritability of alcohol intake is attributable to nonadditive gene action. Effects of cultural transmission that have been reported in adolescence are not present in adulthood.
authors.affiliation: Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands, EMGO Institute for Health and Care Research, Vrije Universiteit Medical Center, Amsterdam, the Netherlands.
authors.forename: Jenny H D A
authors.initials: JH
authors.lastname: van Beek
authors.affiliation: Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands, EMGO Institute for Health and Care Research, Vrije Universiteit Medical Center, Amsterdam, the Netherlands.
authors.forename: Marleen H M
authors.initials: MH
authors.lastname: de Moor
authors.affiliation: Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands, EMGO Institute for Health and Care Research, Vrije Universiteit Medical Center, Amsterdam, the Netherlands.
authors.forename: Lot M
authors.initials: LM
authors.lastname: Geels
authors.affiliation: Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands, EMGO Institute for Health and Care Research, Vrije Universiteit Medical Center, Amsterdam, the Netherlands.
authors.forename: Gonneke
authors.initials: G
authors.lastname: Willemsen
authors.affiliation: Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands, EMGO Institute for Health and Care Research, Vrije Universiteit Medical Center, Amsterdam, the Netherlands, Neuroscience Campus Amsterdam, Amsterdam, the Netherlands.
authors.forename: Dorret I
authors.initials: DI
authors.lastname: Boomsma
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000208:ethnology* / Q000235:genetics*; D003469:Culture; D005260:Female; D006801:Humans; D007206:Individuality; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000208:ethnology; D012042:Registries; D055815:Young Adult