Brain, Sociobiology, and Evolution in Primates

  • H. Hemmer
Conference paper
Part of the Proceedings in Life Sciences book series (LIFE SCIENCES)

Abstract

Socialization in primates can be understood essentially as a function of the information processing ability of the CNS, which can be roughly measured in terms of relative brain size in closely related species groups. Both the cephalization constant (Hemmer 1971, 1974) and the extra neuron number (Jerison 1964, 1973) may be used for relevant quantification, as there is a highly significant correlation of both parameters in primates (7 ape species: r = 0.97, 20 Old World monkey species: r = 0.99; Hemmer 1978). The author has shown in a previous paper (Hemmer 1979) close negative correlations of relative brain size and the social organization as expressed in troop size (r = −0.92) and of relative brain size and reproductive success in captivity (r = −0.90) in the genus Lemur. This has been discussed as reflecting changes in the level of sensibility to stressing influences (psychosocial tolerance) that is caused in over 80% by the informations processing ability. The lemur example led to the conclusion that the sociobiological place of each primate species may be seen as resultant from two opposite processes, both of them depending on progressive cephalization, i.e., decreasing psychosocial tolerance and increasing social learning plasticity, paired with aspiration to social ties. This resulted in an oscillation concept of social group evolution in primates. For progressive primate cephalization a continual change has been postulated between zones of high social tolerance, large social group size, high population density in relatively open habitats and relative evolutionary stability, and zones of low tolerance, small group size, low population density mostly in forest habitats and high evolutionary lability.

Keywords

Autocorrelation Primatol Cepha 

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References

  1. Bauchot R, Stephan H (1966) Données nouvelles sur l’encephalisation des insectivores et des prosimiens. Mammalia 30: 160–196CrossRefGoogle Scholar
  2. Bauchot R, Stephan H (1969) Ecephalisation et niveau évolutif chez les simiens. Mammalia 33: 235–275CrossRefGoogle Scholar
  3. Qutton-Brock TH, Harvey PH (1977) Primate ecology and social organization. J Zool London 183: 1–19CrossRefGoogle Scholar
  4. Crook JH, Gartlan JS (1966) Evolution of primate societies. Nature (London) 210: 1200–1203CrossRefGoogle Scholar
  5. Hemmer H (1971) Beitrag zur Erfassung der progressiven Cephalisation bei Primaten. Proc 3rd Int Congr Primatol Zürich 1970, vol I. Karger, Basel, pp 99–107Google Scholar
  6. Hemmer H (1974) Progressive Cephalisation und Dauer der Jugendentwicklung bei Primaten, nebst Bemerkungen zur Situation bei Vor- und Frühmenschen. In: Bernhard W, Kandier A (eds) Bevölkerungsbiologie. Fischer, Stuttgart, pp 527–533Google Scholar
  7. Hemmer H (1978) Socialization by intelligence: Social behavior in carnivores as a function of relative brain size and environment. Carnivore 1: 102–105Google Scholar
  8. Hemmer H (1979) Beobachtungen zur Soziobiologie madagassischer Lemuren. Z Kölner Zoo 22: 43–51Google Scholar
  9. Jerison HJ (1964) Interpreting the evolution of the brain. In: Garn SM (ed) Culture and the direction of human evolution. Detroit, pp 45–73Google Scholar
  10. Jerison HJ (1973) Evolution of the brain and intelligence. Academic Press, London New YorkGoogle Scholar
  11. Jolly A (1975) Die Entwicklung des Primatenverhaltens. Fischer, StuttgartGoogle Scholar
  12. Orlick M, Mletzko H-G (1975) Auswertung biologischer Zeitreihen mittels Fourier- oder Autokorrelationsanalyse. Biol Rundsch 13: 265–276Google Scholar
  13. Strumwasser F, Schlechte FR, Streeter J (1967) The internal rhythms of hibernators. In: Fisher KC et al (eds) Mammalian hibernation, vol III. Oliver & Boid, Edinburgh London, pp 110–139Google Scholar
  14. Vogel C (1979) Der Hanuman-Langur (Presbytis entellus), ein Parade-Exempel für die theoretischen Konzepte der „Soziobiologie? Verh Dtsch Zool Ges Jahresvers 72: 73–89Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1981

Authors and Affiliations

  • H. Hemmer
    • 1
  1. 1.Institut für Zoologie der Johannes Gutenberg-UniversitätMainzGermany

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