title: Sex Differences in Genetic and Environmental Influences on Longitudinal Change in Functional Ability in Late Adulthood.
abstract: OBJECTIVE
  To determine the extent to which genetic and environmental factors contribute to individual and gender differences in aging of functional ability.
  
  
  METHODS
  Twenty assessments of functional ability are collected as part of the longitudinal Swedish Adoption/Twin Study of Aging from 859 twins aged 50-88 at the first wave. Participants completed up to 6 assessments covering a 19-year period. Factor analysis was used to create 3 factors: flexibility, fine motor skills, and balance.
  
  
  RESULTS
  Latent growth curve analysis demonstrated increasing disability and variability after age 70. For flexibility, results indicated significant sex differences in mean change trajectories but no sex differences in components of variance. No sex differences were found for fine motor movement. For balance, there were no sex differences in mean change trajectories; however, there was significant genetic variance for changes in balance in women after age 70 but not for men.
  
  
  CONCLUSIONS
  Although idiosyncratic environmental influences account for a large part of increasing variance, correlated and shared rearing environmental effects were also evident. Thus, both microenvironmental (individual) and macroenvironmental (family and cultural) effects, as well as genetic factors, affect maintenance of functional ability in late adulthood.
authors.affiliation: Department of Psychology, Indiana University Southeast, New Albany. dfinkel@ius.edu.
authors.forename: Deborah
authors.initials: D
authors.lastname: Finkel
authors.affiliation: Institute for Gerontology, School of Health Sciences, Jönköping, Sweden.
authors.forename: Marie
authors.initials: M
authors.lastname: Ernsth-Bravell
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden. Department of Psychology, University of Southern California, Los Angeles.
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Pedersen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D004777:Environment; D005260:Female; D059647:Gene-Environment Interaction; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009048:Motor Skills / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D012737:Sex Factors; D013548:Sweden / Q000453:epidemiology
keywords: Aging; Behavior genetics; Functional ability; Longitudinal; Sex differences; Twins