Socioeconomic Status Modifies Heritability of IQ in Young Children

  title={Socioeconomic Status Modifies Heritability of IQ in Young Children},
  author={Eric Turkheimer and Andreana P. Haley and Mary Waldron and Brian M. D’Onofrio and Irving I Gottesman},
  journal={Psychological Science},
  pages={623 - 628}
Scores on the Wechsler Intelligence Scale for Children were analyzed in a sample of 7-year-old twins from the National Collaborative Perinatal Project. A substantial proportion of the twins were raised in families living near or below the poverty level. Biometric analyses were conducted using models allowing for components attributable to the additive effects of genotype, shared environment, and non-shared environment to interact with socioeconomic status (SES) measured as a continuous variable… 

Figures and Tables from this paper

Childhood Socioeconomic Status Amplifies Genetic Effects on Adult Intelligence
The results suggest that rather than setting lower and upper bounds on intelligence, genes multiply environmental inputs that support intellectual growth, which implies that increasing SES may raise average intelligence but also magnifies individual differences in intelligence.
Socioeconomic Background and Gene–Environment Interplay in Social Stratification across the Early Life Course
To what extent are differences in education, occupational standing, and income attributable to genes, and do genetic influences differ by parents’ socioeconomic standing? When in a children’s life
Parental socioeconomic status and child intellectual functioning in a Norwegian sample.
The analyses showed that SES explained a significant part of the variance of the full-scale Wisc-III score and two WISC-III indices (Verbal Comprehension and Freedom from Distractibility).
Genetic and Environmental Influences on Cognitive Abilities in Extreme Poverty
In a sub-Saharan sample of early teenage twins, in a first study of biopsychosocial gene–environment interaction in extreme poverty, substantial genetic influence on cognitive abilities and shared environmental influences were similar to those found in adolescents growing in Western affluent countries.
Polygenic Influence on Educational Attainment
This work measures the genetic predisposition of siblings to educational attainment using polygenic scores, and finds subtle differences between sibling fixed-effect estimates of the genetic effect versus those based on unrelated individuals.
Emergence of a Gene × Socioeconomic Status Interaction on Infant Mental Ability Between 10 Months and 2 Years
A Gene × Environment interaction was evident on the longitudinal change in mental ability over the study period, and genetic influences emerged over the course of development, with larger genetic influences emerging for infants raised in higher-SES homes.
Little Evidence That Socioeconomic Status Modifies Heritability of Literacy and Numeracy in Australia.
Shared environmental influences on Grade 3 literacy were greater with low family SES, and no other moderating effects of SES were significant, compared with results from the United States and the United Kingdom.
Socioeconomic status and genetic influences on cognitive development
The largest, most population-diverse consideration of the hypothesis that genetic influences on cognitive abilities are larger for children raised in more advantaged environments in Florida found no evidence of SES moderation of genetic influence on test scores, suggesting that articulating gene-environment interactions for cognition is more complex and elusive than previously supposed.
Large Cross-National Differences in Gene × Socioeconomic Status Interaction on Intelligence
A meta-analysis of tests of Gene × SES interaction on intelligence and academic-achievement test scores, allowing for stratification by nation (United States vs. non–United States), and conducting rigorous tests for publication bias and between-studies heterogeneity found clear support for moderately sized Gene → SES effects.


Genetic and environmental influences on vocabulary IQ: parental education level as moderator.
How parental education level moderates the genetic and environmental contributions to variation in verbal IQ is examined in 1909 non-Hispanic Whites and African American sibling pairs from the National Longitudinal Study of Adolescent Health.
Implications of the restricted range of family environments for estimates of heritability and nonshared environment in behavior-genetic adoption studies.
Group and individual-difference adoption designs lead to opposite conclusions concerning the importance of shared environment (SE) for the child outcomes of IQ and antisocial behavior. This paradox
Multiple regression analysis of twin data
A multiple regression model for the analysis of twin data is described in which a cotwin's score is predicted from a proband's score and the coefficient of relationship, which provides a powerful test of the extent to which the difference between the mean for probands and that for the unselected population is heritable.
IQ and social class
The nature of nurture: Genetic influence on “environmental” measures
Abstract Evidence for genetic influence on environmental measures will emerge in quantitative genetic analyses if genetically influenced characteristics of individuals are assessed by these
Variance components models for gene-environment interaction in twin analysis.
  • S. Purcell
  • Environmental Science
    Twin research : the official journal of the International Society for Twin Studies
  • 2002
As well as elucidating environmental pathways, consideration of gene-environment interaction in quantitative and molecular studies will potentially direct and enhance gene-mapping efforts.
The Mixed or Multilevel Model for Behavior Genetic Analysis
The mixed or multilevel model is proposed as an alternative approach to existing behavior genetic analysis—an alternative to correlation analysis, the DeFries-Fulker analysis, and structural equation modeling, and analysis of the possible genetic basis for friendship selection.
Individual and Group Differences in Adoption Studies of IQ
In the last 5 years, the Colorado and Texas adoption projects have replicated and elaborated the findings of the classical adoption studies of this century: IQs of adoptees are more strongly related
Nature-nurture reconceptualized in developmental perspective: a bioecological model.
The authors propose an empirically testable theoretical model that goes beyond and qualifies the established behavioral genetics paradigm by allowing for nonadditive synergistic effects, direct measures of the environment, and mechanisms of organism-environment interaction through which genotypes are transformed into phenotypes.