About a decade ago, a friend was rehabilitating a wounded squirrel and asked for ideas: the squirrel had stopped eating. My personal expertise in squirrels extends only as far as an unbridled glee at seeing them pillage various neighbors’ “squirrel-proof” birdfeeders, but I offered to help. The squirrel seemed healthy. The food seemed appropriate. We felt stumped.
On a whim, I removed all the food from the squirrel’s serving bowl, tied some to a string, and dangled it awkwardly out of reach. That is, I dangled the food in a position that I naively assumed would be out of reach. Within fifteen minutes, the squirrel had found a way to climb a nearby curtain, sway it purposefully, then arch its back across empty space to nab a snack. The squirrel engaged in dramatic acrobatics to obtain the exact same food it hadn’t touched in the food bowl.
I found myself thinking of this squirrel while reading Dr. Calhoun’s Mousery and Rat City, a pair of recently published books that both discuss the life, experiments, and legacy of biologist John Calhoun. The most famous of Calhoun’s experiments featured an indoor colony of mice. With no predation and unlimited access to food and water, Calhoun wanted to determine how crowded the seventy-square-foot enclosure would get. After several generations, the mice in this colony ceased breeding; five years later, the last denizens died of old age.
From this single finding (which was contradicted by prior results from other researchers studying overpopulation in mice, and which none of Calhoun’s own future experiments ever reproduced), Calhoun extrapolated a wide range of conclusions about human behavior and the dire ramifications of humanity’s increasing urbanization.
Calhoun’s ideas were widely celebrated in the popular press—in the late 1960s and early 1970s, journalists were eager to promulgate sweeping theories that could explain social unrest—and authors such as Tom Wolfe and Hunter S. Thompson began to incorporate the term “behavioral sink” into their writing, the idea that an overly urban population would inevitably reach a state of terminal decrepitude.
But upon Calhoun’s first formal presentation of his findings to a scientific audience, his work was panned. No effort had been made to control the rodents’ olfactory environment over time (and we now know that mouse olfaction is so sensitive that the presence of a T-shirt previously worn by a male rather than a female lab technician is enough to trigger a dramatic spike in cortisol and a nearly two-fold dampening of pain response)—the mice were living in an indoor space with recycled air and impermeable floors that was never cleaned during the five-year experiment, with a visiting Newsweek journalist describing the “rank mouse smell” as “overpowering.” There was virtually no genetic variation among the mice, heavily inbred to create a near-clonal true breeding line before the experiment began. And inside the habitat, there was no novel visual, auditory, or olfactory stimulation other than the occasional visits of human researchers, which caused the mice to swarm.
And yet, Calhoun still clung dogmatically to his initial conclusions, espousing the theory that individuals (whether inbred mice or urban-dwelling humans) who had been exposed to crowded conditions in youth were likely to become permanently deviant and adopt “unnatural” practices such as excessive self-beautification or homosexuality. (Interested readers might consult Eliot Schafer’s Queer Ducks, which stresses that researchers of that era did not understand the frequency of homosexual behavior in nature because their internal biases caused them to assume that all mating events were between heterosexual pairs, even in species with such subtle sexual dimorphisms that it is difficult to assess biological sex in the field.) Then, near the end of his career, Calhoun became infatuated with supposedly utopian ideals such as cybernetic brain uploading and other technological replacements of our essential nature as embodied biological organisms.
Beneath the surface of either of these books, there are hints of a tragic cautionary tale that echoes Calhoun’s own conclusions about rodents: an acute period of deprivation can have lifelong consequences. There was a time when Calhoun was thirty-six years old with two kids and a mortgage and impending unemployment. Up until that time, Calhoun had been an assiduous ecologist who studied birds and rodents simply to learn more about their behaviors in the wild. But that is not where the big research money lies. And so during that year, as Calhoun scrambled to find a new source of income, he began to talk about the importance of studying rodents to gain insight into our own mental health, and he never stopped. Even when the conclusions that he could draw about human behavior based on the rodent studies were tendentious at best.
And as his (tendentious) ideas were translated into the popular press, the consequences often grew even worse. Citing how many more rodents could be stored in a given space if they were stacked in isolated cages than if they were allowed to congregate, developers constructing housing for underserved human populations adopted isolation and segregation as their design goals rather than considering what type of interactions would best foster a sense of community, leading to travesties such as the Pruitt-Igoe housing complex.
I assume that most readers, even if interested in Calhoun’s life and works, will read only one of these new books. Dr. Calhoun’s Mousery has more detail linking Calhoun’s life to popular culture at the time, noting almost every moment when his ideas were alluded to in songs, television spots, magazine articles, and more. Written by a biologist, this book also amply describes Calhoun’s struggles to find lab space and funding commensurate with his visions. Rat City has more detail about other researchers’ studies that were being conducted contemporaneously with Calhoun’s, and the authors strive to link Calhoun’s ideas to current issues such as the shut-in phenomenon in modern Japan, the shift in funding from psychiatric care to the prison-industrial complex in America, and the dramatic increase in the use of prescription medications to address mental conditions. Rat City also uses a mix of past and present tense to describe past events—writing that Calhoun is building a mouse enclosure, to make the prose sound more immediate—that I dislike, especially since there are several sections where the verb tense careens from past to present within the space of a paragraph or even a single sentence.
To my mind, both books seem excessively laudatory of Calhoun’s work, but I imagine that someone would have to believe that Calhoun was an insightful thinker in order to write such carefully researched biographies. I agree with the sentiment that we can better understand human minds through the study of other animals; we share neural architecture and our cognitive capabilities seem to exist on the same continuum. And yet, it seems odd to me that Calhoun chose to draft press releases, scientific reports, and research lectures with such strident conclusions. His private notes make clear that Calhoun was aware that the quirks of a particularly instantiated history would have a major influence on the result of experiments like his—another researcher had already shown that mice would exhibit less territoriality if a slightly larger initial seed population was used—but Calhoun still spent much of his life making grand claims extrapolated from an experimental result he’d observed … once.
University of California Press