Behavior Genetics

, Volume 47, Issue 5, pp 507–515 | Cite as

Interaction between Parental Education and Twin Correlations for Cognitive Ability in a Norwegian Conscript Sample

  • Eric Turkheimer
  • Christopher R. Beam
  • Jon Martin Sundet
  • Kristian Tambs
Original Research
First Online:
Received:
Accepted:

Abstract

We examine a sample of Norwegian twin conscripts for evidence of an interaction between parental education and the heritability of general cognitive ability (GA). Ability scores were obtained on 1706 pairs of twins who were conscripted into the Norwegian Armed Forces between 1931and 1960. Education scores were available for mothers and fathers; the majority of the parents had less than a high school education. GA scores were heteroscadistic with respect to mid-parent education, with reduced variability at higher levels of education. Both MZ and DZ twin correlations for GA were linearly and negatively related to mid-parent education, DZ twins substantially more so. When the model was extended to an ACE model consisting of standardized positive ACE variance components, the modification appeared to disappear. Further analysis revealed that this occurred because the steep decline of DZ twin correlations with increasing mid-parent education resulted in a violation of the classical twin model for much of the parameter space. Other phenomena that might result in large declines in DZ twin correlations are considered, along with implications for other studies of socioeconomic interactions with the heritability of GA in European samples.

Keywords

Intelligence Parental education Gene by environment interaction Military conscripts 
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Notes

Compliance with ethical standards

Conflict of interest

Eric Turkheimer, Christopher R. Beam, Jon Martin Sundet, Kristian Tambs declare that they have no conflict of interest.

Informed consent

This study was approved by the Institutional Review Board of the University of Virginia.

Statement of human and animal rights

No experimental animals were used in the study.

References

  1. Bates TC, Hansell NK, Martin NG, Wright MJ (2016) Intelligence when does socioeconomic status (SES) moderate the heritability of IQ? No evidence for g× SES interaction for IQ in a representative sample of 1176 Australian adolescent twin pairs. Intelligence, 56:10–15. doi: 10.1016/j.intell.2016.02.003 CrossRefGoogle Scholar
  2. Beam CR, Turkheimer E (2013) Phenotype-environment correlations in longitudinal twin models. Dev Psychopathol, 25:7–16. doi: 10.1017/S0954579412000867 CrossRefPubMedGoogle Scholar
  3. Bronfenbrenner U, Ceci SJ (1994) Nature-nurture reconceptualized in developmental perspective: a bioecological model. Psychol Rev 101(4):568–586CrossRefPubMedGoogle Scholar
  4. Dolan CV et al (2014) GE Covariance through phenotype to environment transmission: an assessment in longitudinal twin data and application to childhood anxiety. Behav Genet 44:240–253. doi: 10.1007/s10519-014-9659-5 CrossRefPubMedPubMedCentralGoogle Scholar
  5. Eaves LJ (2006) Genotype × environment interaction in psychopathology: fact or artifact? Twin Res Hum Genet, 9(1):1–8. doi: 10.1375/183242706776403073 CrossRefPubMedGoogle Scholar
  6. Fischbein S (1980) IQ and social class. Intelligence 4(1):51–63CrossRefGoogle Scholar
  7. Hansen (2006) Contributions to the history of the Psychological Services in the Norwegian Army (In Norwegian). Forsvarets Institutt for Ledelse.Google Scholar
  8. Magnus P, Nance WE, Berg K (1983) Predicting zygosity in Norwegian twin pairs born 1915–1960. Clin Genet 24(2):103–112CrossRefPubMedGoogle Scholar
  9. Muthén LK, Muthén BO (2015) Mplus statistical analysis with latent variables: user’s guide. Muthén & Muthén, Los AngelesGoogle Scholar
  10. Notes from the Psychological Services of the Norwegian Armed Forces (1956). OsloGoogle Scholar
  11. Purcell S (2002) Variance components models for gene—environment interaction in twin analysis. Twin Res, 5(6):554–571CrossRefPubMedGoogle Scholar
  12. Rowe DC, Jacobson KC, Van den Oord EJ (1999) Genetic and environmental influences on vocabulary IQ: parental education level as moderator. Child Dev 70(5):1151–1162CrossRefPubMedGoogle Scholar
  13. Scarr-Salapatek S (1971) Race, social class, and IQ. Science, 174(4016):1285–1295CrossRefPubMedGoogle Scholar
  14. Sundet JM, Tambs K, Magnus P, Berg KA (1988) On the question of secular trends in the heritability of intelligence test scores: a study of Norwegian twins. Intelligence 12:47–59CrossRefGoogle Scholar
  15. Sundet JM, Eilertsen DE, Tambs K, Magnus P (1994) No differential heritability of intelligence test scores across ability levels in Norway. Behav Genet 24(4):337–339CrossRefPubMedGoogle Scholar
  16. Tambs K, Sundet JM, Magnus P (1988) Genetic and environmental effects on the covariance structure of the Norwegian army ability tests. Personality Individ Differ 9(4):791–799CrossRefGoogle Scholar
  17. Tucker-drob EM, & Bates TC (2015) Large cross-national differences in gene × socioeconomic status interaction on intelligence. Psychol Sci. doi: 10.1177/0956797615612727 Google Scholar
  18. Turkheimer E, Horn EE (2012) Interactions between socioeconomic status and components of variation in cognitive ability. Springer, New YorkGoogle Scholar
  19. Turkheimer E, Haley A, Waldron M, Onofrio BD, Gottesman II (2003) Socioeconomic status modifies heritability of IQ. Psychol Sci 14(6):623–629CrossRefPubMedGoogle Scholar
  20. van der Sluis S, Willemsen G, de Geus EJC, Boomsma DI, Posthuma D (2008) Gene-environment interaction in adults’ IQ scores: measures of past and present environment. Behav Genet, 38(4):348–360. doi: 10.1007/s10519-008-9212-5 CrossRefPubMedPubMedCentralGoogle Scholar
  21. Waller NG, Muthen BO (1992) Genetic Tobit factor analysis: quantitative genetic modelling with censored data. Behav Genet 22(3):265–292CrossRefPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2017

Authors and Affiliations

  1. 1.University of VirginiaCharlottesvilleUSA
  2. 2.University of Southern CaliforniaLos AngelesUSA
  3. 3.University of OsloOsloNorway
  4. 4.Norwegian Institute of Public HealthOsloNorway

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