The world doesn’t wait up for us, does it? The changes of the past few days are earthshaking and distracting. This is something I began working on weeks ago. I’m just throwing it out there.
Ethologist John B. Calhoun's experiments in the 1950s and 60s explored the effects of ideal living conditions on social behavior in rats and mice. In his “rodent utopias,” where food, water, and protection were abundant, he sought to study the effects of population density and the absence of external challenges.
As populations grew and space became limited, the social structure collapsed. Rats displayed abnormal behaviors—aggression, withdrawal, neglect of offspring, and eventually, a cessation of reproduction altogether—a phenomenon Calhoun termed the “behavioral sink.”
Calhoun interpreted these results as evidence that overcrowding disrupted social interactions and caused societal collapse. He believed this highlighted the dangers of unchecked population growth, drawing parallels between rat colonies and human urban environments.
However, his experiments conflated population density with the absence of external challenges. In the wild, even high densities don’t lead to such collapses because external pressures—scarcity, predators, and competition—structure animal societies. By removing these pressures, Calhoun created a purposeless environment, amplifying the behavioral breakdowns he observed. Later critics suggested this lack of meaningful roles and challenges, not density alone, might have been the driving factor.1
The dramatic breakdowns Calhoun described fit neatly into mid-century fears about overpopulation, resource scarcity, and urban decay, echoing themes from The Population Bomb. His vivid imagery of collapsing social order captured imaginations, overshadowing scrutiny of his methods and conclusions. It wasn’t until later that researchers revisited his work and argued that purpose, not just space, was crucial for psychological and social health. Even a rat needs problems to solve, obstacles to overcome. All mammals do.2
As ethologist Erik Pianka put it, “That's what's wrong with animals in zoos. They don't have any ecologies anymore. They might as well be dead.”
A utopian life without struggle isn’t life. It’s zombie-existence.
Although I dismiss the relevance of the behavioral sink to population density, I accept its relevance to problem-solving and overcoming obstacles. Calhoun’s experiments may have been about rats, but they hold a mirror to human tendencies: our addiction to short-term solutions and the comfort of resorting to Big Daddy for protection.
Cheap labor is a quick fix to labor shortages. But human beings aren’t machine parts: their culture and struggles come along with their skills—or lack thereof. Future generations always pay the cost.3
The same applies to self-defense. In unstable and lethal environments, reliance on a great power creates dependency. Without the challenge of standing on one’s own, you might as well be dead.
Names you can look up for further thoughts along these lines: Jonathan Freedman, Anthony Leeds, John F. Schumaker, Keith G. Still.
And they certainly do need rat buddies. Some Israeli researcher has criticized all the rat studies that focus on one, single, stressed-out rat. They are highly social creatures. Studying what one, stressed-out rat does tells us noting about, for example, human addiction.
Not to mention cheapening the attitude to honest labor… but I digress.