But Surely the Problem will Fix Itself: Behavioral Sinks
While we find the Calhoun stuff a little pop-sci for our tastes, its predictive capabilities make it worth including. At the time these experiments were released, no one seriously expected a massive population collapse to occur in post-scarcity societies. Per the Criterion of Shot Calling, we would be remiss to ignore its potential implications.
Your instinct when looking at the demographic collapse problem may be that it will eventually resolve itself. This is actually our view as well—once the sociological profiles associated with prosociality and openness to other cultures (which make people susceptible to sterilizing memes) have been bred out of the population, things will stabilize. However, there is evidence that even our view might be overly rosy.
In his famous “Rat Utopia” experiment, ethnologist John B. Calhoun gave a population of rats access to unlimited food and water (though limited space), removed all natural predators, and ensured perfect rat temperatures (68°F—20°C) to see what would happen after a few generations. While many people still complain about world poverty, the objective truth is that functionally we live in a world today where a significant portion of humans experience something akin to these “Rat Utopias” in that food and water are not the limiting factors on reproduction in the way they used to be.[[1]](#_ftn1)
Note: Like most famous experiments from this era, there is some reason to think[[2]](#_ftn2) the results of these experiments may have been exaggerated or p-hacked. However, they also appeared to have been predictive of future social trends that had not yet come to pass when the experiments were conducted, which leads us to think they are at least worth considering.
Calhoun reported:
“The mice couldn’t form normal social bonds or engage in complex social behaviors such as courtship, mating, and pup-rearing. Instead of interacting with their peers, males compulsively groomed themselves; females stopped getting pregnant. Effectively, says Ramsden, they became “trapped in an infantile state of early development”, Ultimately, the colony died out. “There’s no recovery, and that’s what was so shocking to [Calhoun],” says Ramsden.[[3]](#_ftn3)
“Among the males the behavior disturbances ranged from sexual deviation to cannibalism and from frenetic overactivity to a pathological withdrawal from which individuals would emerge to eat, drink and move about only when other members of the community were asleep.”
“The common source of these disturbances became most dramatically apparent in the populations of our first series of three experiments, in which we observed the development of what we called a behavioral sink. The animals would crowd together in greatest number in one of the four interconnecting pens in which the colony was maintained. As many as 60 of the 80 rats in each experimental population would assemble in one pen during periods of feeding. Individual rats would rarely eat except in the company of other rats. As a result, extreme population densities developed in the pen adopted for eating, leaving the others with sparse populations.”[[4]](#_ftn4)
“The few secluded spaces housed a population Calhoun called “the beautiful ones.” Generally guarded by one male, the females—and few males—inside the space didn’t breed or fight or do anything but eat and groom and sleep. When the population started declining the beautiful ones were spared from violence and death, but had completely lost touch with social behaviors, including having sex or caring for their young.”[[5]](#_ftn5)
We find it telling that the first human populations to experience demographic collapse are those which were first to enter rough human equivalents to “Rat Utopias.” Population has first begun to rapidly decline among human groups that reached levels of development at which the majority of their population no longer experienced food or water constraints a few generations earlier than others.
Specifically, many of the behaviors observed in the Utopia rats have arguably manifested in humans occupying developed economies from the 1970s onward, suggesting this rat experiment was roughly predictive of human societal trends, given these studies were mostly undertaken from the 1940s to the 1960s. For example, the development of a “behavioral sink”[[6]](#_ftn6) in which the rats began to cluster could be seen as analogous to the explosion in urbanism since the studies were conducted. This same trend has begun to appear in our society (after the experiments, so they were predictive of this).[[7]](#_ftn7)
Observations like, “[the] population would assemble in one pen during periods of feeding. Individual rats would rarely eat except in the company of other rats” demonstrate that among many of the rats, compulsive, suicidal ultra- prosociality developed right before the populations began to collapse (some might argue we are seeing analogous behavior in some human populations).
In addition, populations like the “beautiful ones” seem to indicate that a portion of the population in this sort of collapse scenario will retreat from in-person interactions and become obsessed with grooming behavior. Potentially in humans this could be seen as a growing obsession with social validation, to the extent that people “forget” how to breed (perhaps this phenomenon is at play with dropping sex rates and populations shifting to more online—rather than in-person—interaction).
In relation to “a pathological withdrawal from which individuals would emerge to eat, drink and move about only when other members of the community were asleep:” If we see countries like Japan as at a more advanced stage of the Rat Utopia experiment we might see this pattern as being reflected in the Hikikomori[[8]](#_ftn8) phenomenon, in which many individuals stop interacting with society and stay socially isolated as much as possible. (It would be very interesting if this turned out to be predictive and we started seeing Hikikomori behavior in other countries once fertility rates drop below a specific point.)
The question of course is what is really causing the unusual behavior (if it is real). For example, it could be innocuous things like the clustering acculturation and the fact that the rats want to only eat when close to other rats—similar to the study that shows that rats which have all their early sexual experience when wearing a little vest will have trouble having sex without a vest.[[9]](#_ftn9) It could also be some disease or mutational meltdown[[10]](#_ftn10) that was not picked up given Calhoun’s poor experimental protocols caused the unusual behavior and population collapses. The most concerning potential mechanism of action is that he was witnessing a pattern of behaviors which emerged in social mammals as a result of stress caused in post-scarcity environments. (Like how mammals demonstrate a pre-set range of behavior patterns when caged, causing them to do things like pace, pick at their hair, and not mate.)
People have drawn all sorts of wild implications from Calhoun’s experiments, often attributing the results to whatever their particular cause area is. For example, many originally used the experiments to decry overcrowding and overpopulation, even though the study is equally about giving a population of social mammals unlimited food and water (plus in late stages of the experiment, the rats were found to intentionally crowd, leaving large parts of the pen sparsely populated).
For that reason, we won’t extrapolate too much (and we’ll fully admit that our conjecture is nothing more than that), other than to point out that these experiments show that equilibrium may not be a guaranteed outcome of a post-scarcity society. There is a chance that things don’t equalize.
Note: Two follow-up studies were not able to recreate the population collapse but did create many but not all of the other behaviors. Given the number of “universes” or instances of this study that Calhoun created, this might be a rare phenomenon.[[11]](#_ftn11) Also: If any reader is involved in recreating this experiment, please measure testosterone levels. We would be very interested to see if a behavioral sink might at least partially explain recent shifts in male testosterone levels.