The term “behavioral sink” was coined by the research psychologist John B. Calhoun to describe the behavior of rats and mice under conditions of severe overcrowding. During his animal behavior studies at the National Institute of Mental Health in the 1950s and early 1960s Calhoun observed pathological changes in social behavior among rats who were allowed to breed in an environment free of any adverse conditions except the confined dimensions of their living space.
Sociation Today gives a concise summary of Calhoun’s findings:
Animal studies made famous by Calhoun (1962) show that crowding in the animal world results in what he calls the behavioral sink. Normal behavior and reproductive habits fail. Aggressive behavior increases when density passes a certain point as animals compete for resources. In the experience of the reviewer, those who deny any possible connection between any human behavior simply say that humans are not animals so there can be nothing learned from animal experiments. However, human animals do seem to exhibit much lower fertility rates in cities than is true in rural areas.
Carla Garnett describes Calhoun’s work in somewhat more detail at the NIH website:
Working at NIMH in 1954, Calhoun launched several experiments with rats and mice. In his first series of tests, he placed 32 to 56 rodents in a 10- by 14-foot case in a barn on a Montgomery County farm. Using electrified partitions, he divided the space into four rooms. Each was designed to support 12 adult brown Norway rats. Rats could move between the rooms only via the ramps he built. Because Calhoun provided unlimited water and food as well as protection from predators, disease and weather, the critters were said to be in “rat utopia” or “mouse paradise”…
He described the onset of several pathologies: violence and aggression, with rats in the crowded pen “going berserk, attacking females, juveniles and less-active males.” There was also “sexual deviance.” Rats became hypersexual, pursuing females relentlessly even when not in heat.
The mortality rate among females was extremely high. A large proportion of the population became bisexual, then increasingly homosexual, and finally asexual. There was a breakdown in maternal behavior. Mothers stopped caring for their young, stopped building a nest for them and even began to attack them, resulting in a 96 percent mortality rate in the two crowded pens. Calhoun coined a term — “behavioral sink” — to describe the decay.
A paper by Edmund Ramsden and Jon Adams for the Centre for Medical History offers further explanation:
With no predators and with exposure to disease kept at a minimum, Calhoun described his experimental universes as “rat utopia,” “mouse paradise.” With all their visible needs met, the animals bred rapidly. The only restriction Calhoun imposed on his population was of space — and as the population grew, this became increasingly problematic. As the pens heaved with animals, one of his assistants described rodent “utopia” as having become “hell.”
Males became aggressive, some moving in groups, attacking females and the young. Mating behaviors were disrupted. Some males became exclusively homosexual. Others became pansexual and hypersexual, attempting to mount any rat they encountered. Mothers neglected their infants, first failing to construct proper nests, and then carelessly abandoning and even attacking their pups. In certain sections of the pens, infant mortality rose as high as 96%, the dead cannibalized by adults. Subordinate animals withdrew psychologically, surviving in a physical sense but at an immense psychological cost. They were the majority in the late phases of growth, existing as a vacant, huddled mass in the centre of the pens. Unable to breed, the population plummeted and did not recover. The crowded rodents had lost the ability to co-exist harmoniously, even after the population numbers once again fell to low levels. At a certain density, they had ceased to act like rats and mice, and the change was permanent.
By the time Calhoun’s work was popularized in the mid-1960s, the “population explosion” craze had reached its height. His work, with its obvious analogies to human behavior in densely populated urban areas, was cited to support widespread anxiety over population growth.
Calhoun was a self-popularizer, and was more than happy to help his work reach a wider public. He encouraged the application of his studies to human behaviors in pathologically crowded conditions, and the analogies were indeed compelling: sexual deviance, aggression, loss of fertility, etc. Life in the crowded noir underworld —captured so effectively many years later in the film Blade Runner — was put forward as a parallel to the behavior of rats in their confined “utopias”.
Calhoun viewed his studies optimistically, and saw them as a way to find solutions to problems associated with human overcrowding. In later years he devised modified living spaces which muted the “behavioral sink” pathologies and allowed the subject animals to cope more readily with increased population densities. His results were applied by architects, city planners, and behavioral psychologists to the design of living spaces in urban conditions.
Unfortunately for Calhoun, his reputation was cemented in the early years of his fame by popular writers such as Paul Ehrlich and Tom Wolfe. He was the Prophet of Doom, not the Apostle of Hope, and his optimistic attitude was unable to alter that perception.
In the seventies and eighties when the zeitgeist changed, his work fell out of fashion, and even into disrepute. As it became obvious that we were not headed for Soylent Green, and that there was no imminent population disaster, his work seemed irrelevant. Population pressure had been eased by the suburban safety valve, and conditions in the cities seemed to resemble less and less those in Calhoun’s rat pens — at least to the formerly urban middle class, and it was their opinion that counted.
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Moreover, the idea of applying data about animal behavior to humans became more and more frowned upon. “Nature” gave way to “Nurture”, and deterministic biological explanations of human activity were deemed ideologically unacceptable. Calhoun was pushed towards the dustbin of history, and his later years were embittered by his waning influence and marginalization.
I first encountered the studies of John B. Calhoun when I was in college almost forty years ago. His work was so compelling that ever since then I have kept him in mind while tracking news and social trends, in an attempt to determine whether the behavioral sink is indeed emerging among humans.
As later sociological studies observed, crowding in the city centers was reduced as the affluence of Western society increased. More and more people developed the ability to migrate out of high-density areas and move to the suburbs and the edge cities where there was more living space.
During the intervening four decades, however, every single indicator of a human behavioral sink has increased.
Fertility has dropped to catastrophically low levels across the entire Western world, to the extent that some cultures are at risk of disappearing permanently.
Promiscuity is rampant, and children become sexually active at ever-earlier ages. Sexual deviance, particularly homosexuality, has not only increased, it has moved from being illegal and socially disapproved of, through tolerance, then acceptance, until finally it is celebrated and even considered normative in some places.
Gang-related behavior and violence is at epidemic levels. In parts of Europe the violent crime rate has increased to a point that would have been unimaginable just a generation ago.
Some of Calhoun’s other indicators are harder to measure. The incidence of child abuse, molestation, and neglect seems to have increased dramatically, but that may be due to greater awareness and reporting of the crimes. In the popular imagination, however, the abuse of children is perceived as growing more and more frequent.
All of the above would seem to correlate with an increased crowding of humans within a confined space, but such is demonstrably not the case. So what is going on?
To discover possible answers to this conundrum, it is necessary to look more closely at Calhoun’s work. Ramsden and Adams outline the theoretical framework behind the “behavioral sink” research:
Central to Calhoun’s experimental design was his contention that there exists an upper limit to the number of meaningful social interactions that an individual could cope with before stress became a factor. This innate limit determined a maximum group size — a figure Calhoun set at twelve in both rats and man. As population density increased it became ever more difficult for an individual to control the frequency of social contact. The result was unwanted interaction, leading to adverse reactions such as hostility and withdrawal, and ultimately, to the type of social and psychological breakdown seen during the latter stages in his crowded pens. [emphasis added]
In other words, it was not crowding per se that triggered pathological responses, but the increase in unwanted contacts with fellow members of the group. Too much social stimulation is as bad for the individual as too little, and when the amount of excessive stimulation reaches a critical point, the “sink” behavior kicks in:
The way Calhoun describes it, behavior becomes more and more erratic until, eventually, the behavioral sink emerges like a vortex. Thereafter it acts as an accelerant, exacerbating the effects of the other pathological behaviors: “The unhealthy connotations of the term are not accidental,” Calhoun wrote, “a behavioral sink does act to aggravate all forms of pathology that can be found within a group.”
Calhoun dubbed his artificial rat environments “utopias”, and the temptation to draw parallels with modern Western societies is hard to resist. We, too, live in an optimum environment, artificially created to take care of all our needs. Calhoun drew the parallel himself, and explicitly stated the risks:
With its subsequent descent into “hell,” he seemed to be questioning by extension the viability of the welfare democracy — the more resources we supplied to the population, the more profound our problems became.
Our conception of “utopia” as an environment in which the basic requirements of the population were met and social hierarchy obsolete, failed to account for social, biological, and psychological needs: the border between utopia and dystopia was not merely fine and easily crossed, it was fictitious. As he stated in an interview: “Human beings thus face a predicament: If we try to make everybody totally happy, we’ll destroy mankind.”
So here we are, denizens of a Calhounian Ratopia, with all its wonderful benefits, and exhibiting all the predicted signals for an imminent descent into the behavioral sink. Yet our population density is not high enough to explain our current collective behaviors. What can possibly account for this discrepancy?
The answer lies in the theoretical basis for the pathological responses exhibited by rats in the behavioral sink: they were experiencing too much social stimulation.
As pointed out by Calhoun’s critics, human beings are not rats, and our neuropsychology is immensely more plastic than that of rats. Our perceptions are molded and our behaviors displaced by social factors, so that our instincts may be rewired to such an extent that the original stimulus/response patterns are barely recognizable.
Much of our environment now contains stimuli that are experienced as social interaction even when no personal contact is involved. Picture a commuter stuck in a traffic jam on the freeway. He experiences the presence of all those other cars in terms of social interactions, becoming just as angry and frustrated as if they were people invading his personal space. Strictly speaking, the density of humans on that freeway is very low — hundreds of square feet per individual. Yet the driver experiences the process as if he were in a packed bar at happy hour.
Watch him take out his cell phone and call or text a series of friends and coworkers — another string of social interactions with no other humans nearby. Follow him to work and see him open his email and listen to his voicemail — interaction, interaction, interaction…
At home that night he watches the talking heads yell at each other on the TV. More vicarious interactions there. Then a movie or a sitcom with sexual stimuli, violence, anxiety, and tension — as if he were on a crowded street, experiencing each of these as a personal contact.
I submit that our modern affluent technological society has replaced much real personal interaction with a virtual simulacrum, and it has ramped up the frequency of stimuli to such a level that the “behavioral sink” responses have been triggered and are now causing us to circle the social drain.
This is not a cause for complete pessimism, because the instinctive responses producing the behavioral sink may well have evolved as a last-ditch desperate mechanism by the social group to relieve pathological overcrowding. As Jim Moore points out in a paper for the Anthropology Department of the University of California at San Diego, from the point of view of population ecology, behavior that is pathological under normal circumstances may actually be adaptive when conditions are grave and threaten the entire group or even the species.
Calhoun’s rat populations were so damaged by their behavioral sink that the population never recovered. But the conditions he imposed upon his rats were totally artificial, and would never occur in nature. It seems likely that under natural circumstances the “sink” behaviors would induce a dieback and a population collapse, but one from which the group could recover.
If the human analogy holds, then sometime in the next twenty to sixty years we will face a catastrophic worldwide collapse of the population, coupled with a radical transformation of our social environment so that the burden of excessive unwanted social interactions will be relieved.
If I am correct, a period of unimaginable human suffering and devastation lies ahead. But beyond the horror lies the chance for a rebirth of civilization. Those who survive will be able to live in a world that is less burdened with pathological levels of stimuli and is thus more conducive to the formation of social structures that align with the instinctual needs of the human species. We will be starting over.
It brings to mind Isaiah 37:31:
And the surviving remnant of the house of Judah shall again take root downward and bear fruit upward.
This post was inspired by a discussion at Rebellious Vanilla’s blog about the “behavioral sink” as it applies to human populations.