title: Genetic and environmental influences on thin-ideal internalization.
abstract: OBJECTIVE
  Current research on the etiology of thin-ideal internalization focuses on psychosocial influences (e.g., media exposure). The possibility that genetic influences also account for variance in thin-ideal internalization has never been directly examined. This study used a twin design to estimate genetic effects on thin-ideal internalization and examine if environmental influences are primarily shared or nonshared in origin.
  
  
  METHODS
  Participants were 343 postpubertal female twins (ages: 12-22 years; M = 17.61) from the Michigan State University Twin Registry. Thin-ideal internalization was assessed using the Sociocultural Attitudes toward Appearance Questionnaire-3.
  
  
  RESULTS
  Twin modeling suggested significant additive genetic and nonshared environmental influences on thin-ideal internalization. Shared environmental influences were small and non-significant.
  
  
  CONCLUSIONS
  Although prior research focused on psychosocial factors, genetic influences on thin-ideal internalization were significant and moderate in magnitude. Research is needed to investigate possible interplay between genetic and nonshared environmental factors in the development of thin-ideal internalization.
authors.affiliation: Department of Psychology, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Suisman
authors.forename: Shannon M
authors.initials: SM
authors.lastname: O'Connor
authors.forename: Steffanie
authors.initials: S
authors.lastname: Sperry
authors.forename: J Kevin
authors.initials: JK
authors.lastname: Thompson
authors.forename: Pamela K
authors.initials: PK
authors.lastname: Keel
authors.forename: S Alexandra
authors.initials: SA
authors.lastname: Burt
authors.forename: Michael
authors.initials: M
authors.lastname: Neale
authors.forename: Steven
authors.initials: S
authors.lastname: Boker
authors.forename: Cheryl
authors.initials: C
authors.lastname: Sisk
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Klump
mesh_terms: D000293:Adolescent; D000856:Anorexia Nervosa / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology*; D001828:Body Image; D002648:Child; D003469:Culture; D004038:Diet, Reducing / Q000523:psychology; D004200:Diseases in Twins / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology*; D005260:Female; D059647:Gene-Environment Interaction; D020022:Genetic Predisposition to Disease / Q000235:genetics / Q000523:psychology; D006801:Humans; D056865:Ideal Body Weight; D007389:Internal-External Control; D008402:Mass Media; D012042:Registries; D012932:Social Facilitation; D011795:Surveys and Questionnaires; D013851:Thinness / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology*; D055815:Young Adult