Definitions

John Calhoun's experiment

 

Some characteristic behaviours 
 
Calhoun's experiment - introduction 
 

A social experiment involving mice which should have the same impact on humanity as the apple falling on Newton's head. Unfortunately, this has not happened due to... unknown factors or probably due to politics.

Eight mice given perfect living conditions with everything they needed. The population rose, fell and became extinct within 4 years. It was repeated several times using mice and rats and the results were the same:

Due to the lack of challenges, extinction was inevitable.

This was John Calhoun's deepest concern - I shall largely speak of mice, but my thoughts are on man,....

This is one of the most enlightening works concerning the depths of human nature, so all available information has been collected here.

  1. Calhoun's experiment - description
  2. Calhoun's experiment - important insights
  3. Calhoun's experiment - conclusions

  4. The inbreeding issue
  5. Calhoun's experiment - links

  6. Calhoun's experiment - Questions & Answers

Calhoun's experiment - original description 
 

Fig. The number of mice in the Calhoun's experiment

 

1. The original study of John Calhoun:

John B. Calhoun, "Death Squared: The Explosive Growth and Demise of a Mouse Population" Proc. roy. Soc. Med. Volume 66 January 1973, pp80-88

[Original copy of this work at http://www.ncbi.nlm.nih.gov]

 

2. Description in Wikipedia [2014.05.25]:
In July 1968 four pairs of mice were introduced into the Utopian universe. The universe was a 9-foot (2.7 m) square metal pen with 54-inch-high (1.4 m) sides. Each side had four groups of four vertical, wire mesh "tunnels". The "tunnels" gave access to nesting boxes, food hoppers, and water dispensers. There was no shortage of food or water or nesting material. There were no predators. The only adversity was the limit on space.

Initially the population grew rapidly, doubling every 55 days. The population reached 620 by day 315, after which the population growth dropped markedly. The last surviving birth was on day 600. This period between day 315 and day 600 saw a breakdown in social structure and in normal social behavior. Among the aberrations in behavior were the following:

  • expulsion of young before weaning was complete,
  • wounding of young,
  • inability of dominant males to maintain the defense of their territory and females,
  • aggressive behavior of females,
  • passivity of non-dominant males with increased attacks on each other which were not defended against.
After day 600, the social breakdown continued and the population declined toward extinction. During this period females ceased to reproduce. Their male counterparts withdrew completely, never engaging in courtship or fighting. They ate, drank, slept, and groomed themselves – all solitary pursuits. Sleek, healthy coats and an absence of scars characterized these males. They were named "the beautiful ones".
[Wikipedia 2014.05.25]

 

3. Transcript from the film Mouse Utopia Experiment on Youtube:
In a unique experiment that took years to complete, Doctor Calhoun used white mice to study population growth and its effects on individual behaviour.

In this sixteen cell mouse habitat, utopian conditions of nutrition, comfort and housing were provided for the potential population of over three thousand mice. [...] Factors which normally control population growth such as predation by owls and cats were eliminated. Transmissible disease were also reduced. In effect, the mouse universe simulated the present situation of the continually expanding population of humans.

To see how Dr Calhoun's mouse universe grew, we use the familiar population graph again. Within the first one hundred days, the mice went through the period Dr Calhoun called, "strive". This was the period of adjustment. Territories were established and nests were made. The next period lasted about two hundred and fifty days. The population of the mice doubled every sixty days. This was called the "exploit" period. The use of resources become unequal. Although each living unit was identical in structure and opportunities, more food and water was consumed in some areas. As the population increased, most mice associated eating and drinking with the presence of others. And crowding developed in certain units. The third period, consisting of three hundred days, found the population of mice leveling off. This was called the "equilibrium" period. Dr Calhoun noticed that the newer generations of young were inhibited, since most space was already socially defined.

At this time, some unusual behaviour become noticeable. Violence become prevalent. Excess males strived for acceptance, were rejected and withdrew. Huddling together, they would exhibit brief flurries of violence amongst themselves. The effects of violence became increasingly visible. Ceratin individuals became targets of repeated attacks. These individuals would have badly chewed and scarred tails. Other young mice growing into adulthood exhibited an even different type of behaviour. Dr Calhoun called these individuals "the beautiful ones". Their time was devoted solely to grooming, eating and sleeping. They never involved themselves with others, engaged in sex, nor would they fight. All appeared as a beautiful exhibit of the species with keen, alert eyes and a healthy well-kept body. These mice, however, could not cope with unusual stimuli. Though they looked inquisitive they were, in fact, very stupid.

Dr Calhoun called the last period the "die" phase, leading the population into extinction. Although the mouse utopia could house 3000, the population began to decline at 2200. In the shift from the equilibrium to the die phase, each animal became less aware of associates, despite all animals being pushed closer together. Dr Calhoun concluded that the mice could not effectively deal with the repeated contact of so many individual. The evidence of violence increased to the point where most individuals had had their tails bitten to some degree. Eventually, the whole mouse population perished.
[...]
The larger the population, the less care a mother gives to her nest and young.

 

4. Part-transcript from the film "Critical mass":
Link to the most important part of the movie "Critical mass" conected with the Calhoun's experiment.

 

Calhoun's experiment - important insights 
 

Conditions of the mouse utopia 
  • No shortage of food, water and nesting material.
  • No predators.
  • Limited opportunities for transmissible disease.
  • The only adversity: space limitation - the size of the habitat was predicted to host 3840 mice.
Phase A - The phase of social adjustment (strive period) 
Duration The important insights
Day 1 - introduction of 4 males and 4 females
Day 104 - first litters are born
  • (1) Considerable social turmoil among the 8 mice until they became adjusted to each other and to their expanded surroundings.
  • (2) Territories were established and nests were made.
Phase B - The phase of most rapid growth (exploit period) 
Day 105 - rapid population growth
Day 314
  • (1) Population doubling time is about 55 days
  • (1) Social organization established – frequency of litters proportional to social dominance
  • (1) The births tended to be concentrated in some sets of nest boxes (dominant males), while others (non-dominant males - withdrawn males = WM) had few or none.
  • (2) Although each living unit was identical in structure and opportunities, more food and water was consumed in certain areas. As the population increased, most mice associated eating and drinking with the presence of others. And crowding developed in certain units.
  • (1) At the end of this phase there were 3 times as many socially immature mice as there were socially established older ones.
Phase C - The stagnation phase (equilibrium period) 
Day 315 - slow population growth
Day 559
  • (1) Population doubling time is about 145 days
  • (1) The male ability to defend territory declines
  • (1) The nursing females become aggressive, essentailly taking over the role of the territorial males. This aggression generalized to their own young who were attacked, wounded, and forced to leave home several days before normal weaning.
  • (2) At this time, some unusual behaviour became noticeable. Violence became prevalent. Excess males strived for acceptance, were rejected and withdrew. Social disorder became visible – a WM would attack a passive WM, who in turn would attack another WM. Certain individuals became targets of repeated attacks. These individuals would have badly chewed and scarred tails.
  • (3) Socially withdrawn male 29 makes a pan-sexual approach to male 16 who he recently saw attacked. Note how one assumes the female role. Males exhibit sexual behaviour towards other males; you have rat homosexuality. They begin mounting the young.
  • (1) Incidence of conception decline and resorption of foetuses increases and dissolution of maternal behaviour is observed. This lead to non-reproducing females.
  • (1) By midway in phase C, essentially all young were prematurely rejected by their mothers. They started independent life without having developed adequate affective bonds.
  • (1) Considering that there were 256 nest retreat sites in the 16 cells, one would not expect shelter to be a limiting factor until the population exceeded 3840. Due to the tendency of many animals to choose to crowd together in numbers in excess of 15 per nest site, at the peak population size of 2200 mice, 20% of all nest sites were usually unoccupied. Thus, there were always opportunities for females to select an unoccupied space for rearing young if they so chose.
  • (1) Social disorder – a WM would attack a passive WM, who in turn would attack another
Phase D - The death phase (die period) 
Day 560 - negative population growth
Day 1588 - end of study
  • (1) Population increase abruptly ceased on day 560 after colonization.
  • (1) Incidence of pregnancies decline very rapidly with no young surviving.
  • (1) The last conception took place about day 920
  • (1) Male counterparts to non-reproducing females were named the "beautiful ones". They never engaged in sexual approaches toward females, and they never engaged in fighting. Their behavioural repertoire became largely confined to eating, drinking, sleeping and grooming.
  • (1) The capacity for reproduction terminated.
  • (3) The last thousand animals born never learned to develop the social behaviours, they never learned to be aggressive, which is necessary in defence of home sites; not engaging in any stressful activity, and only paying attention to themselves, they groomed themselves well so they looked like very fine specimens.
  • (2) Other young mice growing into adulthood exhibited an even different type of behaviour. Dr Calhoun called these individuals "the beautiful ones". Their time was devoted solely to grooming, eating and sleeping. They never involved themselves with others, engaged in sex, nor would they fight. All appeared as a beautiful exhibit of the species with keen, alert eyes and a healthy well-kept body. These mice, however, could not cope with unusual stimuli. Though they looked inquisitive they were, in fact, very stupid.

 

Calhoun's experiment - conclusions 
 

All conclusions drawn by socialist (& state) scientists constantly connect extinction with overpopulation:

The conclusions drawn from this experiment were that when all available space is taken and all social roles filled, competition and the stresses experienced by the individuals will result in a total breakdown in complex social behaviors, ultimately resulting in the demise of the population.
[Wikipedia 2014.05.25]

However in the Calhoun's papers there are clear evidences that this is not so:

  • all available space was not taken
  • WM (Withdrawn Males) had no social roles so they withdrew

 

John Calhoun conclusions:

  • The demise of a population contradicts prior knowledge which indicates that when a population declines to a few remnant groups, some individuals will reinitiate its growth.

  • Dr. Halsey Marsden (1972) placed some mice from the mid-third of phase D into new universes at very low densities. all exhibited nearly total loss of capacity for developing a structured society or for engaging in the full repertoire of reproductive behaviours.

  • For an animal so simple as a mouse, the most complex behaviours involve the interrelated set of courtship, maternal care, territorial defence and hierarchical intragroup and intergroup social organisation. When behaviours related to these functions fail to mature, there is no development of social organisation and no reproduction. As in the case of my study reported above, all members or the population will age and eventually die. The species will die out. For an animal so complex as man, there is no logical reason why a comparable sequence of events should not also lead to species extinction. If opportunities for role fulfilment fall far short of the demand by those capable of filling roles, and having expectations to do so, only violence and disruption of social organisation can follow. Individuals born under these circumstances will be so out of touch with reality as to be incapable even of alienation. Their most complex behaviours will become fragmented. Acquisition, creation and utilisation of ideas appropriate for life in a post-industrial cultural-conceptual-technological society will have been blocked. Just as biological generativity in the mouse involves this species' most complex behaviours, so does ideational generativity for man. Loss of these respective complex behaviours means death of the species.

 

John Calhoun's collaborator's conclusions:

  • The larger the population, the less care a mother gives to her nest and young.

 

Non-academic conclusions drawn by people educated in life:


  • The principal factor is the lack of social education in the young

  • Due to the abundance of food and water and lack of predators, there was no need to perform any actions to acquire resources and/or avoid danger. So the young have no opportunity to see such actions, learn (bad pupils often lose their lives) and, later, use them effectively.

  • Utopia (when one has everything, at any moment, for no expenditure) declines responsibility, effectiveness and awareness of social dependence, and finally, as Dr Calhoun's study showed, leads to self-extinction.

  • Contrarily, difficult conditions instigate better coping mechanisms for the population, leading to its growth, strengthening and reinforcement. [See S-nastu hypothesis i supercompensation]

Principle conclusions:


The lack of challenges gradually spoils the behaviour

of subsequent generations of a population.

This degeneration is inevitable

and leads to eventual self-extinction.

 

 

Due to the lack of challenges, the extinction

of a population is inevitable.

It lasts several generations, but is inexorable.

 

The inbreeding issue 
 
  • As I read the description of the experiment, I noticed that the degenerative effect of inbreeding was not taken into account, which could explain the 100% mortality at it's end. Inbreeding can result in physical and mental degeneration, infertility and destructive behaviour. This has been shown in royal lineage and isolated wolf packs.

    It is a very interesting phenomenon, and needs to be researched in the context of this experiment. It is only then when the experiment, in my eyes, will be complete and important from the scientific perspective.
    Zofia D-J (Szwecja) 2015.09.25

    It is not necessarily the case. In Lucas Bridges' book "The Uttermost Part of the Earth", small islands belonging to the archipelago of the Land of Fire were inhabited by 2-3 pairs of rabbits:

    On some of these boat trips Father took passengers of a different species. In the Beagle Channel, and others farther south, there are innumerable islands, mostly rocky, but with a good deal of bush, grass and wild celery growing on them. Father realized that these islands, if stocked with rabbits, would yield welcome food for natives and for any shipwrecked crews who might be stranded there. Accordingly, he brought some rabbits from the Falklands. He took good care that they did not escape onto the main island, nor did he release them on the larger islands in the Channel, lest they should become a pest to future farmers. But on any small island that he considered suitable he would land two or three pairs. Where there was good sandy soil and bush they thrived and increased exceedingly. Some years later H.M.S. Sirius anchored off one of these islands, and the whole ship’s company landed in two batches on consecutive days. Hunting the descendants of the couple of pairs set free there by my Father provided them with plenty of exercise, and over six hundred rabbits were caught – one for every man on the ship.

    In Calhoun's experiment 4 pairs were used, yet Lucas Bridges mentions 2-3 pairs. Because he was alive from 1874-1949, there is no way he would ever have heard about John Calhoun (1917-1995) and his experiment from 1968-1972.

    According to Lucas Bridges, rabbit populations initiated by 2-3 pairs will, after a few decades and in a natural environment, develop large populations very quickly.

  • Reconstruction of the species of European bison.

    As a result of genetic testing of the possibility of reproduction of the endangered european bison, scientists came to the conclusion that only six individuals were to be used for the reconstruction of the species. These six bison are, therefore, the ancestors of all lowland european bison living today.

    [Source]

 

Calhoun's experiment - links 
 

 

Calhoun's experiment - Questions & Answers
 

  1. Helene O. Netherlands:

    I have not found the answer as to why the population would completely die out after the growth has come to a standstill and starts to decline. Why does it not go up again at a certain point? Can you shed any light on this?

    Sophisticated living objects are born with a given structure and given basic behavioural patterns due to its DNA. Moreover, they are equipped with the possibility of acquiring new skills. The neonate has the opportunity to learn from the parents, the environment and the community. This learning encapsulates the essential behaviours of their own and their offsprings survival.

    Firstly, they learn how to feed - in John Calhoun's study, due to effortless provision, the youngsters did not learn this. So they could not learn how to act pursuantly. If they are not able to acquire food, they cannot acquire other things, like a partner, community etc.

    Secondly, the subsequent generations did not learn what they should do gradually, from generation to generation, they became worse and worse teachers. This led to a total loss of breeding, because children gradually lost their knowledge of bringing up their offspring and how to get a partner.

    Initial survival, understood as survival of myself, is due to DNA. The survival of more sophisticated species depends on nurturing acquired from those around us. Scientists call these MEME's. The study shows how MEMEs degenerate causing extinction.

    Creatures with higher cognitive abilities would be able to restart their normal pursuant life, provided the degeneration is not deep enough and they have to fight to survive. The mice in Calhoun's experiment had no such an opportunity to resurrect their community.