The Malleability of Intelligence Is Not Constrained by Heritability

  • Douglas Wahlsten


In The Bell Curve, Herrnstein and Murray claim that a high value for heritability of intelligence limits or constrains the extent to which intelligence can be increased by changing the environment.1 In this chapter it is argued that the calculated numerical value of “heritability” has no valid implications for government policies and that evidence of a nonspecific genetic influence on human mental ability places no constraint on the consequences of an improved environment. On the contrary, a very small change in environment, such as a dietary supplement, can lead to a major change in mental development, provided the change is appropriate to the specific kind of deficit that in the past has impaired development. The results of adoption studies, the intergenerational cohort effect, and effects of schooling also reveal that intelligence can be increased substantially without the need for heroic intervention.


Cohort Effect Mental Ability Bell Curve Harvard Educational Review Nutritional Deficiency Disease 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Herrnstein, R J., and Murray, C. (1994), The Bell Curve: Intelligence and Class Structure in American Life, The Free Press, New York.Google Scholar
  2. 2.
    Putnam, C. (1961), Race and Reason. A Yankee View, Public Affairs Press, Washington, D.C.Google Scholar
  3. 3.
    . Jensen, A. (1969), “How Much Can We Boost IQ and Scholastic Achievement,” in Environment, Heredity, and Intelligence, Reprint series No. 2, Harvard Educational Review,1-123. Google Scholar
  4. 4.
    Gottlieb, G. (1992), Individual Development and Evolution. The Genesis of Novel Behavior, Oxford University Press, New York.Google Scholar
  5. 5.
    Lewontin, R. (1974), “The Analysis of Variance and the Analysis of Causes,” American Journal of Human Genetics, 26, 400–411.Google Scholar
  6. 6.
    McGuire, T. R., and Hirsch, J. (1977), “General Intelligence (g) and Heritability (H 2,b 2 ), in I. C. Uzgiris and E Weizmann (Eds.), The Structuring of Experience, Plenum, New York, pp. 25–72.CrossRefGoogle Scholar
  7. 7.
    Wahlsten, D. (1990), “Insensitivity of the Analysis of Variance to Heredity-Environment Interaction,” Behavioral and Brain Sciences,13, 109–161.CrossRefGoogle Scholar
  8. 8.
    Wahlsten, D., and Gottlieb, G. (1997), “The Invalid Separation of Effects of Nature and Nurture: Lessons from Animal Experimentation,” in R. Sternberg and E. Grigorenko (Eds.), Intelligence, Heredity, and Environment,Cambridge University Press, New York, 163–192..Google Scholar
  9. 9.
    Goldberger, A.S. (1978), “The Nonresolution of IQ Inheritance by Path Analysis,” American Journal of Human Genetics, 30, 442–445.Google Scholar
  10. 10.
    Kempthorne, O. (1978), “Logical, Epistemological and Statistical Aspects of Nature-Nurture Data Interpretation,” Biometrics, 34,1–23.MathSciNetCrossRefGoogle Scholar
  11. 11.
    Roubertoux, P.L., and Capron, C. (1990), “Are Intelligence Differences Hereditarily Transmitted?,” Cahiers de Psychologie Cognitive10, 555–594.Google Scholar
  12. 12.
    Taylor, H.F. (1980) The IQ Game. A Methodological Inquiry into the Heredity-Environment Controversy, Rutgers University Press, New Brunswick, NJ.Google Scholar
  13. 13.
    Fisher, R.A. (1951), “Limits to Intensive Production in Animals,” British Agricultural Bulletin, 4,217–218.Google Scholar
  14. 14.
    Kempthorne, O. (1990), “How Does One Apply Statistical Analysis to our Understanding of the Development of Human Relationships?,” Behavioral and Brain Sciences, 13, 138–139.CrossRefGoogle Scholar
  15. 15.
    Lewontin, R. C. (1991), Biology as Ideology. The Doctrine of DNA, Anansi, Toronto.Google Scholar
  16. 16.
    Chase, A. (1977), The Legacy of Malthus. The Social Costs ofthe New Scientific Racism, Knopf, New York.Google Scholar
  17. 17.
    Gottlieb, G., Wahlsten, D., and Lickliter, R. (in press), “The Significance of Biology for Human Development: A Developmental Psychobiological Systems View,” in R.M. Lerner (Ed.), Theoretical Models of Human Development, Vol. 1, Handbook of Child Psychology, 5th ed., Wiley, New York.Google Scholar
  18. 18.
    Platt, S.A., and Sanislow, C.A., III (1988), “Norm-of-Reaction: Definition and Misinterpretation of Animal Research,” Journal of Comparative Psychology, 102, 254–261.CrossRefGoogle Scholar
  19. 19.
    Lee S.M., and Bressler, R. (1981), “Prevention of Diabetic Nephropathy by Diet Control in the db/db Mouse,” Diabetes, 30, 106–111.CrossRefGoogle Scholar
  20. 20.
    Surwit, R.S., Kuhn, C.M., Cochrane, C., McCubbin, J.A., and Feinglos, M.N. (1988), “Diet-Induced Type II Diabetes in C57BL/6J Mice,” Diabetes, 37,1163–1167.CrossRefGoogle Scholar
  21. 21.
    Woo, S.L.C. (1991), “Molecular Genetic Analysis of Phenylketonuria and Mental Retardation,” in P.R. McHugh and V.A. McKusick (Eds.), Genes, Brain, and Behavior, Raven Press, New York, pp. 193–203.Google Scholar
  22. 22.
    Clarke, A.M., and Clarke, A.D.B. (Eds.) (1979), Early Experience: Myth and Evidence, Free Press, New York.Google Scholar
  23. 23.
    Capron, C., and Duyme, M. (1991), “Children’s IQs and SES of Biological and Adoptive Parents in a Balanced Cross-Fostering Study,” Cahiers de Psychologie Cognitive, 11 323–348.Google Scholar
  24. 24.
    Schiff, M., Duyme, M., Dumaret, A., and Tomkiewicz, S. (1982), “How Much Could We Boost Scholastic Achievement and IQ Scores? A Direct Answer from a French Adoption Study,” Cognition, 12, 165–196.CrossRefGoogle Scholar
  25. 25.
    Flynn, J.R. (1987), “Massive IQ Gains in 14 Nations: What IQ Tests Really Measure,” Psychological Bulletin,101 171–191.CrossRefGoogle Scholar
  26. 26.
    Clarke, S.C.T., Nyberg, V., and Worth, W.H. (1978), Technical Report on Edmonton Grade III Achievement 1956–1977 Comparisons. Alberta Education, Edmonton.Google Scholar
  27. 27.
    Ericsson, K.A., Krampe, R.T., and Tesch-Romer, C. (1993), “The Role of Deliberate Practice in the Acquisition of Expert Performance,” Psychological Review, 100, 363–406 CrossRefGoogle Scholar
  28. 28.
    Wagner, R.K., and Oliver, W.L. (1995) “How to Get to Carnegie Hall: Implications of Exceptional Performance for Understanding Environmental Influences on Intelligence,” in D.K. Detterman (Ed.), Current Topics in Human Intelligence, Vol. 5, The Environment,Ablex, Norwood, NJ, pp. 87–102.Google Scholar
  29. 29.
    Weisberg, R.W. (1986), Creativity, Genius and Other Myths, Freeman, New York.Google Scholar
  30. 30.
    Ceci, S J. (1991), “How Much Does Schooling Influence General Intelligence and its Cognitive Components? A Reassessment of the Evidence,” Developmental Psychology, 27, 702–722.Google Scholar
  31. 31.
    Heyns, B.L. (1978), Summer Learning and the Effects of Schooling,Academic Press, New York.Google Scholar
  32. 32.
    Ferreira, F., and Morrison, F.J. (1994) “Children’s Metalinguistic Knowledge of Syntactic Constituents: Effects of Age and Schooling,” Developmental Psychology, 30,663–678.CrossRefGoogle Scholar
  33. 33.
    Varnhagen, C.K., Morrison, F.J., and Everall, R. (1994), “Age and Schooling Effects in Story Recall and Story Production,” Developmental Psychology, 30, 969–979.CrossRefGoogle Scholar
  34. 34.
    Morrison, F.J., Smith, L., and Dow-Ehrensberger, M. (1995), “Education and Cognitive Development: A Natural Experiment,” Developmental Psychology, 31, 789–799.CrossRefGoogle Scholar
  35. 35.
    Bisanz, J., Dunn, M., and Morrison, F.J. (1995) “Effects of Age and Schooling on the Acquisition of Elementary Quantitative Skills,” Developmental Psychology, 31, 221–236.CrossRefGoogle Scholar
  36. 36.
    Hedges, L.V., and Olkin, I. (1985), Statistical Methods for Meta Analysis,Academic Press, Orlando.zbMATHGoogle Scholar
  37. 37.
    Campbell, F.A., and Ramey, C.T. (1994) “Effects of Early Intervention on Intellectual and Academic Achievement: A Follow-Up Study of Children from Low-Income Families,” Child Development, 65, 684–698.CrossRefGoogle Scholar
  38. 38.
    Ramey, C.T., Yeates, K.O., and Short, E J. (1984), “The Plasticity of Intellectual Development: Insights from Preventive Intervention,” Child Development, 55, 1913–1925.CrossRefGoogle Scholar
  39. 39.
    Wasik, B.H., Ramey, C.T., Bryant, D.M., and Spading, J J. (1990), “A Longitudinal Study of Two Early Intervention Strategies: Project CARE,” Child Development, 61,1682–1696.CrossRefGoogle Scholar
  40. 40.
    Ramey, C.T., Bryant, D.M., Wasik, B.H., Spading, J J., Fendt, K.H., and LaVange, L.M. (1992), “Infant Health and Development Program for Low Birthweight, Premature Infants: Program Elements, Family Participation, and Child Intelligence,” Pediatrics, 89, 454–465.Google Scholar
  41. 41.
    Achenbach, T.M., Howell, C.T., Aoki, M.F., and Rauh, V.A. (1993), “Nine-Year Outcome of the Vermont Intervention Program for Low Birth Weight Infants,” Pediatrics, 91, 45–55.Google Scholar
  42. 42.
    Brooks-Gunn, J., Klebanov, P.K., Liaw, E, and Spiker, D. (1993), “Enhancing the Development of Low-Birthweight, Premature Infants: Changes in Cognition and Behavior Over the First Three Years,” Child Development, 64, 736–753.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1997

Authors and Affiliations

  • Douglas Wahlsten

There are no affiliations available

Personalised recommendations