Replication of a gene-environment interaction Via Multimodel inference: additive-genetic variance in adolescents' general cognitive ability increases with family-of-origin socioeconomic status

Behav Genet. 2015 Mar;45(2):200-14. doi: 10.1007/s10519-014-9698-y. Epub 2014 Dec 25.

Abstract

The present study of general cognitive ability attempts to replicate and extend previous investigations of a biometric moderator, family-of-origin socioeconomic status (SES), in a sample of 2,494 pairs of adolescent twins, non-twin biological siblings, and adoptive siblings assessed with individually administered IQ tests. We hypothesized that SES would covary positively with additive-genetic variance and negatively with shared-environmental variance. Important potential confounds unaddressed in some past studies, such as twin-specific effects, assortative mating, and differential heritability by trait level, were found to be negligible. In our main analysis, we compared models by their sample-size corrected AIC, and base our statistical inference on model-averaged point estimates and standard errors. Additive-genetic variance increased with SES-an effect that was statistically significant and robust to model specification. We found no evidence that SES moderated shared-environmental influence. We attempt to explain the inconsistent replication record of these effects, and provide suggestions for future research.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Twin Study

MeSH terms

  • Adolescent
  • Adoption
  • Biometry
  • Cognition*
  • Environment
  • Female
  • Gene-Environment Interaction*
  • Genetic Variation
  • Humans
  • Intelligence
  • Intelligence Tests
  • Male
  • Minnesota
  • Models, Statistical
  • Parents
  • Phenotype
  • Sample Size
  • Siblings
  • Social Class*
  • Twins, Dizygotic / genetics
  • Twins, Monozygotic / genetics