John B. Calhoun conducted an experiment known as “Universe 25” with mice in a utopian environment with unlimited resources. Initially, the mice thrived and rapidly reproduced.
As the population grew, social structures began to collapse, resulting in aggressive behavior, social isolation, and withdrawal from normal activities. The mice stopped socializing and reproducing, while the mortality rate of the young suddenly increased. The experiment ended with the complete breakdown of social norms and the eventual extinction of the mouse population, despite the abundance of resources. The young mice that grew up in such an environment were unable to learn normal behaviors and retreated into isolation.
Calhoun believed his conclusions had deep implications for human society, warning about the dangers of overcrowding, social disintegration, and the loss of meaningful social roles. He emphasized that if opportunities for meaningful participation in society became scarce, violence and societal collapse could follow. Critics argued that the experiment oversimplified the complexity of human behavior, but it raised important questions about abundance, social isolation, and resource distribution.
The design of the experiment
The “Universe 25” experiment was designed to represent a paradise for mice. In a controlled environment, four pairs of healthy mice were placed in a nine-square-foot enclosure, equipped with unlimited food, water, and nesting material. The temperature was maintained at a comfortable 20 degrees Celsius, and the space was protected from predators and disease. By all standards, this was a utopia.
Initially, the mice thrived. With no need to forage for food or compete for resources, the population grew rapidly, doubling every 55 days. However, as the number of mice increased, cracks began to appear in this seemingly perfect society. When the population reached 620 individuals, the growth rate slowed, and social structures began to collapse. Mice who could not find a role in the increasingly crowded environment became isolated, withdrawing from social interactions and forming what Calhoun called “behavioral sinkholes.”
As the population continued to grow, the mice exhibited more and more deviant behaviors. Dominant males became hyper-aggressive, attacking others without provocation and engaging in violent, often cannibalistic acts. Mothers abandoned their young, and the mortality rate of the young reached 90% in some parts of the population. Female mice, overwhelmed by the chaos, withdrew from mating and focused obsessively on grooming themselves. Calhoun called these mice “beautiful,” noting their perfect fur and complete disconnection from social and reproductive activities.
The final phase: “The Second Death”
The final phase of the experiment, which Calhoun termed “the second death,” was marked by the complete breakdown of social norms. The young mice, raised in this dysfunctional environment, failed to learn normal behaviors. They showed no interest in mating or social interactions, retreating to the upper parts of the enclosure to live in isolation. The population peaked at 2,200 individuals – far below the capacity of the enclosure, which could accommodate up to 3,000 mice – before rapidly declining into complete extinction. Despite the abundance of food and resources, the mice lost the will to survive.
Implications for human society
Calhoun concluded that his findings had profound implications for human society. “For an animal as complex as man, there is no logical reason why a similar sequence of events could not lead to the extinction of the species,” he wrote in his 1972 study. He warned that if opportunities for meaningful social roles were not available, violence and social disintegration could follow. At the time, his work aligned with concerns about urban overcrowding and “moral decay,” although critics argued that his conclusions oversimplified the complexity of human behavior.
In recent years, the experiment has been revisited by scientists who question its applicability to humans. Medical historian Edmund Ramsden suggested that the collapse of “Universe 25” might not have been caused by overpopulation, but by excessive social interaction and the inability of the mice to establish stable territories. Others pointed out that the design of the experiment – where aggressive mice monopolized resources – reflected issues of inequality and resource distribution in the real world, rather than just abundance.
A thought-provoking experiment
While the parallels between Calhoun’s mouse utopia and human society are not perfect, the experiment raises important questions about the consequences of abundance, social isolation, and the loss of meaningful roles. In an era of technological advancement and material wealth, many societies are grappling with declining birth rates, growing mental health issues, and a sense of alienation. Whether these trends signal the potential for social collapse or are merely a reflection of evolving norms remains to be seen.
What is clear, however, is that Calhoun’s work serves as a warning about the delicate balance required to maintain a healthy societal ecosystem. Future research needs to delve deeper into the interactions between abundance, social dynamics, and mental health to better understand the complexities of human behavior and avoid potential dangers.
