September 17, 2024
3 Time required to read
Book review: How a strange rodent ecologist tried to change the fate of humanity
Biography of the scientist who brought about the fear of the “population explosion”
Non-fiction
The Mouse World of Dr. Calhoun: A strange tale of a famous scientist, a mouse dystopia, and the future of humanity
Lee Alan Dugatkin
University of Chicago Press, 2024 ($27.50)
During the 1960s and 1970s, American society was plagued by a long period of mass panic about the threat of overpopulation. Biologist Paul Ehrlich The Tonight Show Advertise Population explosionHis 1968 discussion of human numbers caused mayhem. The 1973 film “Soylent Green” depicted a squalid hellscape in which surplus humans were processed into food. College students vowed to give up children for the sake of the planet.
Supporting science journalism
If you enjoyed this article, please support our award-winning journalism. Subscribe. By purchasing a subscription, you help ensure a future of influential stories about the discoveries and ideas shaping the world today.
This anxiety originated in part in the laboratory of John Bumpass Calhoun, the enigmatic ecologist who spent decades documenting the deleterious effects of overcrowding on rodents in elaborate experimental “cities.” Calhoun is little known today, but few scientists of his time were more influential: he was a friend of science fiction writer Arthur C. Clarke and featured in the books of naturalist E. O. Wilson and journalist Tom Wolfe, popularizing fears of overpopulation in the process. “The most profound impact of Calhoun’s work has been found far away from academic lecture halls and ivory towers,” writes Lee Alan Dugatkin in his book Science and Technology. Dr. Calhoun’s Rat Housea new biography as unorthodox as its subject. Calhoun’s work has permanently “permeated the public consciousness.”
Calhoun was an unlikely prophet. A naturalist from Tennessee, he led a long-term study in Baltimore in the 1940s, whose main goal was to eradicate urban rats. Calhoun found that about 150 rats lived on each city block, but he thought that number was small, given the “abundant food source in open garbage cans.” He surmised that rat populations were “self-regulating”: when new rats tried to take up residence, residents chased them out. But the unpredictability of Baltimore’s streets, with humans constantly killing rats and tampering with traps, frustrated Calhoun’s analysis. To truly understand rat societies, he decided, he needed to control the rats’ environment.
In the late 1950s, the National Institute of Mental Health gave Calhoun the opportunity to manipulate rats in a converted barn in Maryland. Ever the ingenious designer of experiments, he built enclosures with rat homes and divided the enclosures into “neighborhoods,” creating a rat haven where rats could be observed at their leisure.
This utopia quickly turned into a nightmare. As the rats multiplied, they began to feed and congregate in ever-increasingly dense populations, leading to a social breakdown that Calhoun called “behavioral subsidence.” Packs of lusty males relentlessly pursued females, who neglected their offspring. In some areas, puppy mortality reached 96 percent. Calhoun said the rats suffered from a “pathological togetherness” that could lead to disintegration. In the following years, he turned his attention to mice, but his basic conclusion remained the same: rodents succumb to chaos when their populations explode.
Calhoun wasn’t shy about speculating about the fate of our own species: “Perhaps, if human population growth continues unchecked, we may one day see a human version of socially nervous rodents,” he said. Washington Daily News In one characteristic interview, he said his fears guided and shaped the zeitgeist.
Dugatkin is an evolutionary biologist, a historian of science, and a prolific author who has pored over thousands of pages of material in the Calhoun Archives at Bethesda. He is an incredibly meticulous researcher. But his detailed chronology of Calhoun’s activities sometimes gets bogged down in media reports, conference talks, and recitations of complex experiments. In this whirlwind of detail, Mouseley Dugatkin occasionally loses sight of the biography’s central question: why does Calhoun matter today? Dugatkin acknowledges that “the lasting impact of[Calhoun’s]work is far from that of pioneering behaviorists like Ivan Pavlov.” But he misses an opportunity to explore the social debates that Calhoun’s work provoked. Did the bleak future Calhoun predicted do any harm? The population bomb never exploded, after all.
Calhoun belonged to a generation of scientists who had no qualms about straying from their field; he wrote poetry and science fiction, and consulted on humane prison designs. Dugatkin captures the grand ambition of a man who gazed upon rodents and saw the universe, even though the significance of his work is obscured today. As Dugatkin points out, the disturbing dynamics Calhoun created in his micromanaged “universe” have never been observed in nature. Calhoun didn’t describe a world, he created his own.