The Universe 25 Mouse Experiments

In 1972, John B. Calhoun built an utopia for mice. Every aspect of Universe 25, as this particular model was called, was designed to cater for the well-being of its rodent residents, increase their lifespan, and allow them to mate. It was not the first time the ethologist had built a world for rodents. Colhoun had been creating utopian environments for rats and mice since the 1940s, with consistent results: overpopulation leads to explosive violence and hypersexual activity, followed by asexuality, self-destruction, and extinction.

The full story
Intro to Universe 25

Cannibalism, asexuality, and violence. A society that had collapsed.  What’s going on here? In 1972, John B Calhoun detailed the specifications of an utopia designed for mice: built in the laboratory.

universe 25
Universe 25 environment

Every aspect of Universe 25, as this particular model was called, was designed to cater for the well-being of its rodent residents, increase their lifespan, and allow them to mate. There was abundant food, water, and nesting material. The universe was cleaned regularly. There were no predators, the temperature stable. Paradise. Or maybe not?

Beginning of experiment
Day 1

Four pairs of disease-free mice, selected from the National Institutes of Health’s elite breeding colony, moved in on day one.

It took months for the rodents to familiarize themselves with their new world. Then they started to reproduce and the population increased exponentially, doubling every fifty-five days. Those were the good times in paradise.

Population growth
Day 315

Past day 315, more than six hundred mice now lived in Universe 25, rubbing shoulders on their way up and down the stairwells to eat, drink, and sleep. Population growth slowed.

Young ones found themselves born into a world with far more mice than meaningful social roles. Males faced a lot of competitors to defend their territory against. Many found that so stressful, they gave up. Normal discourse within the community broke down, and with it the ability of mice to form social bonds.

Lone females retreated to isolated nesting boxes on penthouse levels.  Other males, a group Calhoun termed “the beautiful ones,” never sought sex and never fought — they just ate, slept, and groomed, wrapped in narcissistic introspection. Elsewhere, cannibalism, asexuality, and violence became endemic. Mouse society had collapsed.

population peaks
Day 560

On day 560 the population peaked at 2,200 mice. A few survived past weaning until day six hundred, after which there were few pregnancies and no surviving young. As the population had stopped regenerating itself, its path to extinction was clear.

The mice had lost the capacity to rebuild their numbers—many that could still conceive, such as the “beautiful ones” and their secluded singleton female counterparts, had lost the social ability to do so.

the last conception
Day 920

On day 920 was the last conception. The last mouse died on May 23 1973, four years and ten months after colonization. Calhoun later said that the creatures had died two deaths. The first was that of their spirit and their society. The “second death” was that of their physical body.

It was not the first time the ethologist had built a world for rodents. Colhoun had been creating utopian environments for rats and mice since the 1940s, with consistent results: overpopulation leads to explosive violence and hypersexual activity, followed by asexuality, self-destruction, and extinction.

In his widely cited paper, “Population Density and Social Pathology”, Calhoun concluded: No matter how sophisticated we are, once the number of individuals capable of filling social roles greatly exceeds the number of such roles, only violence and disruption can follow.

He then referred to a phenomenon he called “Behavioral Sink”

Behavioral sink
Behavioral sink

Behavioral sink is our desire to be in the presence of others, to be conditioned to seek to be near others, and to be drawn to the crowd, in spite of the conflicts that this can generate. 

Drawing from Calhoun’s popular research, social scientists started to call for restrictions on reproduction as the only possible response to the world’s rising population. Calhoun himself was more optimistic about our future. He argued: as our physical space declines, we are forced to extend a conceptual space — our network of ideas and technologies.

Later in his career he turned to possible solutions and began to build creative universes that minimize the ill effects of overcrowding. 

what do you think?
Universe 25 WDYT

What are your thoughts? Is overcrowding a danger for mankind or does it only affect rodents? And if so, what can save the human psyche? Avoiding eye contact in crowded places is one strategy, but is that enough? To read more about Universe 25, and its cultural impact, read the paper of Edmund Ramsden & Jon Adams. You’ll find a link in the description below.

Source

Dig deeper!

  • Watch Soylent Green, 1973. The film depicts a futuristic society in which overpopulation is so catastrophic and food in such short supply that the populace survives on rations of the titular food product, which turns out to be made from processed human flesh.
  • Watch “In Time”, a Film of 2011 where Time is money, and people out of money die. 
  • Watch Snowpiercer (Netflix, 2020) depicting a society in a train where population has to be controlled and the ecosystem rests on a very thin equilibrium. 
  • Read about Behavioral Sink on Longreads
  • Read about the life and work of John B Calhoun

Classroom activity

In the following activity students will learn about Calhoun’s work and Universe 25

  • Separate the class in groups of 3 or 4.
  • Ask the students how they think society would evolve if everyone had access to food, water, shelter, and ideal conditions of life, and ask them to describe how society would be in 25 years if all of this became immediately available. 
  • Show the students Sprouts video on Universe 25.
  • Ask them if they think the downfall of mice was led by overpopulation and its results or by a lack of survival drive due to the abundance of resources.
  • Ask them if they want to change their answer from the first question.
  • Ask them if they think there are fundamental differences between humans and mice that would justify a different answer for the first question.

Collaborators

  • Script: Edmund Ramsden & Jon Adams
  • Editor: Will Wiles, a London-based author and journalist
  • Screenplay: Jonas Koblin 
  • Artist: Pascal Gaggelli
  • Voice: Matt Abbott
  • Coloring: Nalin
  • Editing: Peera Lertsukittipongsa
  • Sound Design: Miguel Ojeda
  • Fact Checking: Ludovico Saint Amour di Chanaz
  • Production: Selina Bador