Thread: Crowding Study

I have heard about this study for years. A flame war on another forum made me think of it so I looked it up and I thought I would see what everyone thinks. It's a study on overcrowding in rat populations and how they react. Some people have compared it with crowding in major cities on the coasts. The theory is that it might explain the differences in basic beliefs between people who live in high density areas and those who don't.

Thoughts anyone.

Crowding Research

1. Crowding Research

Crowding is defined in terms of a high density of people, and can be either detrimental or pleasant. A classic crowding study was done by Calhoun (1962), who put rats into a physical environment designed to accommodate 50 rats and provided enough food, water, and nesting materials for the number of rats in the environment. The rat population peaked at 80, providing a look at cramped living conditions. Although the rats experienced no resource limitations other than space restriction, a number of negative conditions developed:

(a) The two most dominant males took harems of several female rats and occupied more than their share of space, leaving other rats even more crowded.

(b) Many females stopped building nests and abandoned their infant rats.

(c) The pregnancy rate declined.

(d) Infant and adult mortality rates increased.

(e) More aggressive and physical attacks occurred.

(f) Sexual variation increased, including hypersexuality, inhibited sexuality, homosexuality, and bisexuality.

Calhoun's results have led to other research on crowding's effects on human beings, and these research findings have suggested that high density is not the single cause of negative effects on humans. When crowding is defined only in terms of spatial density (the amount of space per person), the effects of crowding are variable. However, if crowding is defined in terms of social density, or the number of people who must interact, then crowding better predicts negative psychological and physical effects.

Field studies done in a variety of settings such as college dormitories, offshore oil rigs, navy ships, prisons, homes for the aged, and junior high schools, illustrate that social density is associated with negative effects such as social withdrawal and increased psychosomatic complaints. In prison studies, crowded conditions have been associated with increases in health concerns, blood pressure, discipline problems, psychiatric commitments, suicides, violent deaths, and deaths by natural causes.

Crowded individuals adjust their incoming sensations, their attitudes, and their behaviors to reduce the negative aspects of crowding. Women are more likely than men to find high density situations friendly, while men are more likely to experience aggression. This sex difference might be explained by men's greater need for personal space.

Do you believe that Calhoun's studies of crowded rats are applicable to human beings? Create some experiments that involve crowding people. Design a lab experiment or a field experiment. Design a dormitory that minimizes the negative aspects of crowding. (Sources: Calhoun, J. B. 1962. A behavioral sink. In E. L. Bliss (Ed.). Roots of behavior. New York: Harper & Row; Freedman, J. L. 1975. Crowding and behavior. San Francisco: W. H. Freeman; Mueller, C. W. 1984. The environment and social behavior. In A. S. Kahn (Ed.). Social Psychology. Dubuque, IA: Wm. C. Brown; Paulus, P. B. & McCain, G. 1983. Crowding in jails. Basic and Applied Social Psychology, 4, 89-107.)

And from fact page on the Wild Norway Rat.

Wild rats live in colonies. Female rats, usually related to each other, live in little groups of one to six in a little burrow system of their own. They each have their own nest chamber, but they may share the burrow and may raise their young together (called communal nesting). When the offspring are weaned, the young males disperse.

The organization of male rats and the rat mating system changes depending on the population density of the colony. At low densities, a male rat monopolizes a burrow of females. He defends a territory, keeping other males away from the burrow and the surrounding area, and he mates only with the females of his group. One male mating with multiple females is a polygynous mating system. At low densities, Norway rats are therefore territorial and polygynous.

At high densities, males can no longer defend a burrow against intruders. There are simply too many intruders. At high densities, the social system becomes despotic, with one male becoming socially dominant while others become socially subordinate. Males no longer defend female burrows. Instead, when a female comes into heat a group of males rushes her and mates with her sequentially, with little or no competition between themselves. Males may mate with multiple estrus females this way, and females mate with multiple males. This mating system is polygynandrous. At high densities, Norway rats are therefore despotic and polygynandrous.

(Edit: I should have specified that the reason I'm posting here instead of there is because I'm waiting for the flames to die out before even considering it.)