UNIVERSE 25: John Calhoun crouches within his rodent utopia-turned-dystopia that, at its peak, housed approximately 2,200 mice. Calhoun was studying the breakdown of social bonds that occurs under extreme overcrowding, following up on his earlier discovery of the learned "behavioral sink" phenomenon in rats.May 28, 2024)
In John B. Calhoun's early crowding experiments, rats were supplied with everything they needed – except space. The result was a population boom, followed by such severe psychological disruption that the animals died off to extinction.)
Genetic variation, such as better peripheral vision, can make some rats “bright” and others “dull”, but does not determine their intelligence. Nonetheless, Tryon's famous rat-maze experiment demonstrated that the difference between rat performances was genetic since their environments were controlled and identical.)
A social imbalance also took place among the mice: One-third emerged as socially dominant. The other two-thirds turned out less socially adept than their forebearers. As bonding skills diminished among the mice, Universe 25 went into a slow but irreversible decline.)
In the 1950s, Curt Richter, a professor at Johns Hopkins, did a famous drowning rats psychology experiment. This experiment, though cruel, demonstrated the power of hope and resilience in overcoming difficult situations.Jul 16, 2024)
Explanation
[edit]The specific voluntary crowding of rats to which the term "behavioral sink" refers is thought to have resulted from the earlier involuntary crowding: individual rats became so used to the proximity of others while eating that they began to associate feeding with the company of other rats. Calhoun eventually found a way to prevent this by changing some of the settings and thereby decreased mortality somewhat, but the overall pathological consequences of overcrowding remained.[13]
Further, researchers argued that "Calhoun's work was not simply about density in a physical sense, as number of individuals-per-square-unit-area, but was about degrees of social interaction."[14] "Social density" appears to be key.
Applicability to humans
[edit]Calhoun had phrased much of his work in anthropomorphic terms, in a way that made his ideas highly accessible to a lay audience.[7]
Calhoun himself saw the fate of the population of mice as a metaphor for the potential fate of humankind. He characterized the social breakdown as a "spiritual death",[10] with reference to bodily death as the "second death" mentioned in the Biblical verse Revelation 2:11.[10]
Controversy exists over the implications of the experiment. Psychologist Jonathan Freedman's experiment recruited high school and university students to carry out a series of experiments that measured the effects of density on human behavior. He measured their stress, discomfort, aggression, competitiveness, and general unpleasantness. He declared to have found no appreciable negative effects in 1975.[15]
The 1962 Scientific American article came at a time when overpopulation had become a subject of great public interest, and had a considerable cultural influence.[16] However, such discussions often oversimplified the original findings in various ways. It should however be noted that the work has another message than, for example, Paul Ehrlich's now widely disputed[17][18][19] book The Population Bomb.
Calhoun's worries primarily concerned a human population surge and a potentially independent increase in urbanization as an early stage of rendering much a given society functionally sterile. Under such circumstances society will move from some modality of overpopulation towards a much more irredeemable underpopulation. This has been seen in urban populations that have long been noted to have lower fertility than their rural counterparts,[20] but growing use of especially digital media is likely to end up depressing rural population growth as well.[21] As of today this primarily concerns elite population decline,[22] but can due to positive feedback in social diffusion have Calhoun's empirical predictions apply to a much wider segment of society as well.
