John B. Calhoun

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John Calhoun is an American ethologist noted for his fifteen-year population density behavioral study of Norway rats, which he conducted surrounding a farm in Rockville, Maryland. During his studies, Calhoun coined the term "behavioral sink" to describe aberrant behaviors in overcrowded population density situations. Calhoun's rat studies were used as a basis in the development of Edward T. Hall's 1966 proxemics theories.

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[edit] Norway rat study

Beginning in 1947, ethologist John Calhoun conducted a fourteen-year research project in which he studied the population dynamics of wild Norway rats, through multiple generations, confined to quarter-acre outdoor pens surrounding a barn in Rockville, Maryland. In the first stage of his study, Calhoun introduced five pregnant rats into the outdoor pen, being well-stocked with food and free from predators, and let observed the resulting reactions over a twenty-eight month period.

Interestingly, even though five pregnant over this time-span could theoretically produce 50,000 health progeny for this size pen, Calhoun found that the population never exceeded 200 individuals, and stabilized at 150, similar to the Dunbar number. Moreover, the rats were not randomly scattered throughout the pen area, but had organized themselves into twelve or thirteen local colonies of a dozen rats each. He noted that twelve rats is the maximum number that can live harmoniously in a natural group, beyond which stress and psychological effects function as group break-up forces.

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[edit] References

  1. Calhoun, John, B. (1947-58). “Crowding and Social Behavior in Animals.” In Hall, Edward, T. (1966). The Hidden Dimension. New York: Anchor Books. Ch. 3.
  2. Calhoun, John, B. (1962). “A Behavioral Sink.” In Eugene L. Bliss ed., Roots of Behavior. New. New York: Harper & Brothers, Ch. 22.
  3. Calhoun, John, B. (1962). “Population Density and Social Pathology.” Scientific American, Vol. 206 (Feb), pgs. 139-46.
  4. Calhoun, John, B. (1950). “The Study of Wild Animals under Controlled Conditions.” Annals of the New York Academy of Sciences, Vol. 51. pgs. 113-22.
  5. Calhoun, John, B. (1972). “Plight of the Ik and Kaiadilt is seen as a chilling possible end for Man” Smithsonian Magazine. 3: 27-32.

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