21/07/2025
In 1968, American ethologist John Calhoun conducted one of the most terrifying experiments in the history of behavioral science. He called it Universe 25, a model of an ideal society where mice were supposed to live in paradise.
Calhoun built a closed space designed for 3,840 rodents. This «world» had everything: unlimited food, fresh water, constant temperature, complete safety, cleanliness and medical supervision. No diseases, no predators, no competition for resources.
Four pairs of mice were placed in the pen.
At first, everything was going perfectly: the population grew, the mice settled in, took care of their offspring. But at the peak - when the number reached about 2,200 individuals - irreversible changes began.
Males lost interest in females and defending their territory. Many became apathetic or aggressive. Females refused to raise their young, and sometimes killed them. A new category emerged – the so-called “beautiful mice”: physically well-groomed, with perfect fur, but completely passive. They did not fight, did not mate, did not raise offspring. They were only interested in food, sleep and self-care.
Society fell apart. Social bonds were destroyed. Reproduction stopped. Even when numbers dropped sharply and resources were still abundant, the mice could no longer return to normal behavior.
By day 1780 of the experiment, the last mouse had died.
Calhoun’s experiment became a metaphor not only for biologists, but also for philosophers, sociologists, and urbanists. It showed that in conditions of complete abundance, where challenges, struggle, and the need to adapt disappear, society loses its meaning, purpose, and ability to survive.
What was intended as a utopia turned out to be the silence of an extinct paradise.
