In our minds, the end of humanity will usher in a scenario of destruction and chaos everywhere. It will likely be due to nuclear war or an apocalyptic-scale natural disaster. However, it’s possible that our demise could be different… and far more horrifying. This was demonstrated by the terrifying experiment known as “Universe 25.”
This study was conducted between 1954 and 1972, thanks to John B. Calhoun, an American ethologist and behavior researcher. He was the one who highlighted the grim effects of overpopulation in rodents and how this was a reflection of what would happen to the human race.
Universe 25: The End of the Human Race?
While working at the National Institute of Mental Health (NIMH), Calhoun created a Mouse Utopia to conduct an experiment. The mice had unlimited water and food, sufficient space for recreation, and private nesting areas. However, chaos quickly ensued, causing a dramatic population decrease and giving rise to disturbing and pathological behaviors in the rodents. What happened?
Calhoun spent years refining his methods and repeated the experiment 25 times, hence its name “Universe 25.” Each time, the results were identical.
The habitats were designed to be simple yet effective: a 3×4-meter rectangle divided into four equal sections by electric fences. Each section was identically equipped with a food dispenser, water, and nesting areas.
In his final experiment, the space could accommodate 3,840 mice, but the population only reached 2,200 and began to decline from that point, while exhibiting abnormal and destructive behaviors.
The results revealed what Calhoun called the “behavioral sink,” an increase in pathological activities due to the stress associated with high population density.
Dominant males attacked other members, including infants, and females stopped building nests and caring for their young. This led to an infant mortality rate exceeding 90%.
Regardless of the scale of the experiments, the same events always occurred:
- Mice reproduced in large numbers.
- Eventually, stabilization occurred.
- The rodents developed hostile and antisocial behaviors.
- Finally, the population dwindled to extinction.
For Calhoun, the death phase consisted of two stages: the first characterized by the loss of a purpose in life beyond mere existence. This included the loss of the desire to mate, rear young, or establish roles in society. The second stage was the literal end of the way of life and the extinction of Universe 25.
In the final experiment, before all individuals perished, they allowed a pair of males and a pair of females to reproduce. However, their behavior was so severely disturbed that none of the offspring survived.
A Reflection of Humanity?
Although the “Universe 25” experiment was highly controversial, Calhoun’s theory raised concerns as it could serve as a metaphor for humanity’s fate. The similarity in behaviors is indeed terrifying.
“Humans witness increasingly deficient family relationships, lack of care, complete alienation, and such a lack of collective participation that allows people to witness prolonged murder and not even call the police”.
As described by Carl Rogers in the book “Some Social Issues That Concern Me.”
To prevent society from falling into the behavioral sink, Calhoun dedicated part of his later career to exploring different ways of advancing humanity. He believed that city planning was partially responsible for the ways in which inhabitants interact with each other. Better urban planning was necessary.
He also formed an academic team called the “Space Cadets,” whose purpose was to promote the idea of humans settling on other planets. Interestingly, this idea is now shared by many other specialists.
More than six decades have passed since the “Universe 25” experiment, yet questions about the collapse of utopia persist. Ultimately, we can be grateful not to be mice, as we possess reason, science, technology, and medicine… but collective and individual human behavior can often be highly destructive.