cataclysm, an apocalypse, or the end of all ends. Many names have been given throughout history to the end of humanity as we know it. From a philosophical perspective, everything has an end, therefore we have always expected it. Scriptures from various religions tried to describe what the end would look like, but those started to be considered only fairytale stories. Humanity has not really analyzed the possibility of human extinction and how would this really look like from a scientific perspective until 1954 when a man named John B. Calhoun carried out an 18-year-long study named Universe 25.
John B. Calhoun, an American ethologist and behavioural researcher, conducted a study titled “Universe 25” that examined the consequences of overpopulation on rats and made dire predictions that these effects would have on humans. In collaboration with the National Institute of Mental Health, Calhoun developed the ideal Mouse Universe for his research. Unlimited food and water, many floors, and private nesting spaces that first appeared to be rat and mouse utopias gradually devolved into tumultuous overcrowding that caused the population to decline and was then followed by the members’ unsettling and abnormal behaviors.
On the “Universe 25” experiment, which Calhoun repeated 25 times in various scales after years of method development, he saw unsettlingly consistent outcomes each time. These habitats have a straightforward design. Electric fences split the layout’s ten-by fourteen-foot rectangle into four equally sized pieces. Each part included a food hopper, water source, and nesting spaces that were similar to one another. (As shown in the picture below)
The room he planned for his last experiment could have held 3,840 mice, but only 2,200 mice ended up there, and from then on, the population started to fall while showing a range of odd, sometimes destructive behaviours. The outcome demonstrated what Calhoun called the behavioural sink, or an increase in abnormal behaviours brought on by the stress of a large population.
The dominant males occasionally bite and injure the tails of other members, especially young children. This behavioural sink would show up in females as a decreased capacity for raising young and creating nests. Since many females adopted more violent behaviours or would forego motherly responsibilities entirely, the infant death rate exceeded 90%.
Regardless of the scale of the experiments, the same set of events would transpire each time:
- The mice would mate and breed in large quantities.
- Eventually a leveling-off would occur.
- The rodents would develop either hostile or anti-social behaviors.
- The population would trail off to extinction.
According to Calhoun, there were two stages to the death phase: the “first death,” which was characterized by the loss of a reason for living beyond merely existing (such as the desire to mate, raise children, or establish a place in society), and the “second death,” which was the actual death and the extinction of Universe 25.
With their findings, they concluded the experiment while predicting that these pathological alterations would eventually result in the extinction of the colonies. He would select the four healthiest males and females at the end of the experiment and allow them to reproduce, but their behavior had been irrevocably changed, and none of their offspring had survived.
Though wildly controversial when first published, Calhoun’s theory has raised concern over the years that the social breakdown of Universe 25 could ultimately serve as a metaphor for the trajectory of the human race.