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Human Evolution

, Volume 5, Issue 3, pp 241–244 | Cite as

The evolution of brain size and intelligence in man

Article

Abstract

The brain size of hominids has increased approximately threefold during the evolution of the hominids fromAustralopithecus toHomo sapiens. It is proposed that the principal reason for this increase is that larger brains conferred greater intelligence, and greater intelligence conferred a selection advantage.

A number of anthropologists have difficulty accepting this thesis because they believe that brain size is not associated with intelligence in man. Evidence is reviewed, and new evidence from two studies is presented, to show that brain size as measured by head size is positively correlated with intelligence as measured by intelligence tests. On two recent samples statistically significant correlations of .21 and .30 were obtained between estimates of brain size and IQ. It is considered that brain size is positively associated with intelligence in man and that this is the major reason for the increase in brain size of the hominids during the last 3.2 million years.

Key words

brain size intelligence hominid evolution 

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References

  1. Agrawai N., Sinha S.N. &Jensen A.R., 1984.Effects of inbreeding on Raven's matrices. Behavior Genetics, 14: 579–585.CrossRefGoogle Scholar
  2. Bashi J., 1977.Effects of inbreeding on cognitive performance. Nature, 266: 440–442.CrossRefGoogle Scholar
  3. Brandt I., 1978.Growth dynamics of low birth weight infants with emphasis on the perinatal period. In: Human Growth Vol 2 F. Falkner and J. M. Tanner, Eds. Plenum, New York.Google Scholar
  4. Broman S.H., Nichols P.L. &Kennedy W.A., 1975.Preschool IQ, New York and London: J. Wiley.Google Scholar
  5. Cohen T., Block N., Flum Y., Kadar M. &Goldschmidt E., 1969.School attainments in an immigrant population. In The Genetics of Migrant and isolate populations. E. Goldschmidt (ed). Williams and Wilkins, Baltimore.Google Scholar
  6. Engsner G., 1974.Brain growth and motor nerve conduction velocity in children with protein-calorie malnutrition. Acta Universitatis Upsaliensis, 1–60.Google Scholar
  7. Fisher R.A., 1930.The Genetical Theory of Natural Selection. Clarendon Press, Oxford.Google Scholar
  8. Henneberg M., 1987.Hominid cranial capacity change through time: a darwinian process. Human Evolution, 2: 213–220.CrossRefGoogle Scholar
  9. Henneberg M., Budnik A., Pezacka M. &Puch A.E., 1985.Head size, body size and intelligence: intraspecific correlations in Homasapiens sapiens. Homo, 36: 207–218.Google Scholar
  10. Jensen A.R., 1983.Effects of inbreeding on mental-ability factors. Person. Indiv. Diff., 4: 71–87.CrossRefGoogle Scholar
  11. Jerison H.J., 1982.The evolution of biological intelligence. In: Handbook of Human Intelligence. R.J. Sternberg, Ed. Cambridge University Press, Cambridge.Google Scholar
  12. Kohler W., 1925.The Mentality of Apes. Harcourt, Brace and World, New York.Google Scholar
  13. Latham M.C., 1974.Protein-calorie malnutrition in children and its relation to psychological development and behaviour. Physiol Rev, 54: 541–565.Google Scholar
  14. Mackintosh N.J., Wilson B., &Boakes R.A., 1985.Differences in mechanisms of intelligence among vertebrates. Philosophical Transactions of the Royal Society of London, 8: 308, 53–65.Google Scholar
  15. Murdoch J. &Sullivan L.R., 1923.A contribution to the study of mental and physical measurements in normal school children. American Physical Education Review, 28: 209–215, 276–280, 328–330.Google Scholar
  16. Passingham R.E., 1979.Brain size and intelligence in man. Brain, Behaviour and Evolution, 16: 253–270.CrossRefGoogle Scholar
  17. Pearl R., 1906.On the correlation between intelligence and the size of the head. J. of Comp. Neurol. Psychol., 16: 189–199.CrossRefGoogle Scholar
  18. Pearson K., 1906.On the relationship of intelligence to size and shape of head, and to other physical and mental characters. Biometrika, 5: 105–146.CrossRefGoogle Scholar
  19. Plomin R., 1987.The genetics of intelligence. In: Arthur Jensen, Consensus and Controversy. S. Mogdil and C. Mogdil (eds), Falmer Press, London.Google Scholar
  20. Schreider E., 1968.Quelques correlations somatiques des tests mentaux. Homo, 19: 38–43.Google Scholar
  21. Susanne C. &Sporog J., 1973.Etude de correlations existant entre des tests psychotechniques et des mensurations cephaliques. Bulletin Societe Royal Belge Anthropologie et Prehistorie, 84: 59–63.Google Scholar
  22. Weinberg W.A., Dietz S.G., Penick E.C. &McAlister W.H., 1974.Intelligence, reading achievement, physical size and social class. J. Pediatrics, 85: 482–489.CrossRefGoogle Scholar

Copyright information

© Editrice Il Sedicesimo 1990

Authors and Affiliations

  • R. Lynn
    • 1
  1. 1.University of UlsterColeraineNorthern Ireland

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