The Universe-25 Experiment: How Heaven became Hell

As part of a social experiment, paradisiacal conditions were created for the mouse population: unlimited food and drink supplies, the absence of predators and diseases, sufficient space for reproduction. However, as a result, the entire colony of mice became extinct. Why did this happen? And what lessons should humanity learn from this?

American ethologist John Calhoun conducted a number of amazing experiments in the 60-70s of the twentieth century. D. Calhoun invariably chose rodents as test subjects, although the ultimate goal of research has always been to predict the future for human society. 

As a result of numerous experiments on rodent colonies, Calhoun formulated a new term - "behavioral sink", denoting the transition to destructive and deviant behavior in conditions of overpopulation and crowding. 

With his research, John Calhoun gained some fame in the 60s, as many people in Western countries experiencing the post-war baby boom began to think about how overpopulation would affect public institutions and everyone in particular.

The purpose of the experiment "Universe-25" was to analyze the influence of population density on the behavioral patterns of rodents. Calhoun built a real paradise for mice in a laboratory. 

A tank measuring two by two meters and a height of one and a half meters was created, from where the test subjects could not get out. Inside the tank, a constant temperature comfortable for mice was maintained (+20 °C), there was an abundance of food and water, numerous nests for females were created. 

Every week the tank was cleaned and maintained in constant cleanliness, all necessary safety measures were taken: the appearance of predators in the tank or the occurrence of mass infections was excluded. The experimental mice were constantly monitored by veterinarians, their health status was constantly monitored. 

The system of providing food and water was so thought out that 9500 mice could eat at the same time without experiencing any discomfort, and 6144 mice could consume water without experiencing any problems. 

There was more than enough space for mice, the first problems of lack of shelter could arise only when the population reached over 3840 individuals. However, there have never been such a number of mice in the tank, the maximum population size was noted at the level of 2200 mice.

The experiment started from the moment four pairs of healthy mice were placed inside the tank, which took quite a bit of time to get used to, realize what kind of mouse fairy tale they got into, and begin to multiply rapidly. 

Calhoun called the development period phase A, but from the moment the first cubs were born, the second stage B began. This is the stage of exponential population growth in the tank under ideal conditions, the number of mice doubled every 55 days. 

Starting from the 315th day of the experiment, the population growth rate slowed down significantly, now the number doubled every 145 days, which marked the entry into the third phase C. At that moment, about 600 mice lived in the tank, a certain hierarchy and a certain social life were formed. There is physically less space than there was before.

A category of "outcasts" appeared, who were expelled to the center of the tank, they often became victims of aggression. It was possible to distinguish the group of "outcasts" by bitten tails, torn hair and traces of blood on the body. The outcasts consisted primarily of young individuals who had not found a social role for themselves in the mouse hierarchy. 

The problem of the lack of suitable social roles was caused by the fact that in the ideal conditions of the tank, mice lived for a long time, aging mice did not make room for young rodents. Therefore, aggression was often directed at new generations of individuals born in the tank. 

After the expulsion, the males broke down psychologically, showed less aggression, did not want to protect their pregnant females and perform any social roles. Although periodically they attacked either other individuals from the society of "outcasts", or any other mice.

Females preparing for the birth of cubs became more and more nervous, as a result of the increase in passivity among males, they became less protected from accidental attacks. As a result, the females began to show aggression, often fighting to protect their offspring. 

However, the aggression was paradoxically not directed only at others, no less aggressiveness was manifested in relation to their children. Often the females killed their cubs and moved to the upper nests, became aggressive hermits and refused to reproduce. As a result, the birth rate has fallen significantly, and the mortality of young animals has reached significant levels.

Soon the last stage of the existence of the mouse paradise began - phase D, or the phase of death, as John Calhoun called it. The symbol of this stage was the appearance of a new category of mice, called "beautiful". These included males demonstrating uncharacteristic behavior for the species, refusing to fight and fight for females and territory, showing no desire to mate, prone to a passive lifestyle. 

The "beautiful" only ate, drank, slept and cleaned their skins, avoiding conflicts and performing any social functions. They got such a name because, unlike most of the other inhabitants of the tank, there were no traces of brutal battles, scars and torn wool on their bodies, their narcissism and narcissism became legendary. 

The researcher was also struck by the lack of desire among the "beautiful" to mate and reproduce, among the last wave of births in the tank, "beautiful" and single females who refuse to reproduce and run away to the upper nests of the tank became the majority.

The average age of the mouse in the last stage of the mouse paradise was 776 days, which is 200 days higher than the upper limit of reproductive age. The mortality rate of young animals was 100%, the number of pregnancies was insignificant, and soon it was 0. 

The endangered mice practiced homosexuality, deviant and inexplicably aggressive behavior in conditions of an excess of vital resources. Cannibalism flourished with a simultaneous abundance of food, females refused to raise cubs and killed them. The mice were rapidly dying out, and on the 1780th day after the experiment began, the last inhabitant of the "mouse paradise" died.

Anticipating such a catastrophe, D. Calhoun, with the help of his colleague Dr. H. Marden, conducted a series of experiments at the third stage of the death phase. Several small groups of mice were removed from the tank and relocated to equally ideal conditions, but also in conditions of minimal population and unlimited free space. 

No crowding and intraspecific aggression. In fact, the "beautiful" and single females were recreated the conditions under which the first 4 pairs of mice in the tank multiplied exponentially and created a social structure. 

But, to the surprise of scientists, "beautiful" and single females did not change their behavior, refused to mate, reproduce and perform social functions related to reproduction. As a result, there were no new pregnancies, and the mice died of old age. 

Similar identical results were observed in all resettled groups. All the experimental mice died in ideal conditions.

John Calhoun created the theory of two deaths based on the results of the experiment. The "first death" is the death of the spirit. When newborn individuals had no place in the social hierarchy of the "mouse paradise", there was a lack of social roles in ideal conditions with unlimited resources, there was an open confrontation between adults and young rodents, the level of unmotivated aggression increased. 

The growing population size, the increase in crowding, the increase in the level of physical contact - all this, according to Calhoun, led to the appearance of individuals capable only of the simplest behavior.

In an ideal world, in safety, with an abundance of food and water, and the absence of predators, most individuals only ate, drank, slept, and took care of themselves. A mouse is a simple animal, for him the most complex behavioral models are the process of courting a female, reproduction and care of offspring, protection of territory and cubs, participation in hierarchical social groups. The psychologically broken mice refused all of the above. 

Calhoun calls this rejection of complex behavioral patterns the "first death" or "death of the spirit." After the onset of the "first death", physical death ("second death" in Calhoun's terminology) is inevitable and is a matter of short time. As a result of the "first death" of a significant part of the population, the entire colony is doomed to extinction even in the conditions of "paradise".

One day Calhoun was asked about the reasons for the appearance of a group of rodents "beautiful". Calhoun drew a direct analogy with man, explaining that the key feature of a person, his natural destiny is to live under pressure, tension and stress. 

Mice who refused to fight, who chose the unbearable lightness of being, turned into autistic "beauties", capable only of the most primitive functions - the absorption of food and sleep. The "beauties" refused everything complicated and demanding tension and, in principle, became incapable of such strong and complex behavior. 

Calhoun draws parallels with many modern men, capable only of the most routine, everyday actions to maintain a physiological life, but with an already deceased spirit. What is expressed in the loss of creativity, the ability to overcome and, most importantly, to be under pressure. Refusal to accept numerous challenges, escape from tension, from a life full of struggle and overcoming— is the "first death" in John Calhoun's terminology, or the death of the spirit, followed inevitably by a second death, this time of the body.

Perhaps you still have a question: why was D. Calhoun's experiment called "Universe-25"? This was the twenty-fifth attempt of the scientist to create a paradise for mice, and all the previous ones ended with the death of all the experimental rodents…

He conducted his most famous experiment, which made an entire generation think about the future, in 1972 together with the National Institute of Mental Health (NIMH).