Why are lemmings famous for running off cliffs? I'm assuming this is an urban myth. But where does the idea of suicidal lemmings come from?
Let's begin our investigation with a little Google search, shall we? The popular line on the lemming-suicide myth, found easily on debunking sites like Snopes, plays as follows:
1. White Wilderness, a 1958 Disney documentary about arctic wildlife filmed in Alberta, Canada, contains a scene showing lemmings taking the plunge you describe, to florid narration: "Carried along by an unreasoning hysteria, each falls into step for a march that will take them to a strange destiny," etc. 2. However, the whole thing turns out to have been faked. Filmmakers ran the little guys around on a lazy Susan and tossed them manually into a river shot to look like the ocean. Lemmings didn't even live in that part of Alberta; they had to be imported from Manitoba. 3. "Thus," Snopes concludes, "did Disney perpetuate for generations to come the legend of periodic, inexplicable mass suicides by lemmings who die by hurling themselves off of cliffs?"
Perpetuate, sure. But such accounts give Disney undue credit for a misconception that already existed. The lemming mass-suicide story, and all the metaphorical possibilities that attend to it, had been in circulation for a while, as Edmund Ramsden and Duncan Wilson report in a 2010 paper in the British historical journal Past & Present. Scandinavians in the late 1800s recorded observations of the lemmings' grim march to the sea, struck by the animals' ardent devotion to their task—as well as their violent disinclination to be impeded, which inspired the common Norwegian phrase "angry as a lemming."
Ramsden and Wilson go on to describe how observers of the various dramas of the 20th century—Nazism, communism, consumerism—alluded to the suicidal lemming, making it a "recurring motif for modernity": "The lemming became the totemic animal in an age of cultural pessimism, a symbol of an unconscious and mindless urge toward mass self-destruction, and references to its suicide are legion."
Lemmings, by the way, do sometimes end up underwater, but far less melodramatically than suggested. Their populations operate on a regular boom-and-bust cycle. At the end of a boom, which puts pressure on nearby resources, they disperse in search of food. Some wind up at the ocean and attempt to cross it—lemmings can swim—but drown in the process. You'll notice the Norwegians don't say "smart as a lemming."
So, with respect to a weighty word like "suicide," lemmings don't really qualify. Do other nonhuman animals? The issue has captivated thinkers as far back as Aristotle, who described a tormented stallion throwing himself into an abyss. Certainly animals take actions that lead to their deaths, and are assigned posthumous reasons for such by human observers: loss of a mate, loss of an owner, captivity. The stallion, Aristotle surmised, ended it all after realizing he'd inadvertently shtupped his mother—your basic equine Oedipus scenario.
It's not just sexually confused horses, though. Fifty dogs have jumped off Scotland's Overtoun Bridge in as many years. Pods of whales heave themselves onto beaches; captive dolphins drown themselves.
The traditional argument against granting animals too much agency here is that they're thought to possess senses neither of self nor imagination, both facets of higher-order cognitive functioning required for suicide: you must envision the end of life and understand its implications. So, such thinking goes, when an animal offs itself there's always some biological or mechanistic reason: Navigation error, in the case of those beached whales. Underneath that Scottish bridge investigators found a colony of mink, whose anal scent glands apparently drive dogs wild—the pups were just lunging after a good smell.
But this proposition has been called into question by cognitively complex creatures like dolphins, who can recognize themselves in a mirror, suggesting that crucial sense of self. One prominent biopsychologist turned animal advocate, Lori Marino, has argued that dolphins very much do possess the cognitive capabilities needed to understand the implications of doing themselves in. Monkeys and parrots—other social, higher-order thinkers—can engage in self-destructive behaviors, sometimes unto death, under conditions of confinement or emotional distress, but do we call that suicide?
Rather than trying to puzzle out whether animals conform to human notions of suicide, though, Ramsden and Wilson suggest we invert the question: What if we conceived of human suicide—a behavior that's long perplexed scientists—less as an a willful act of imagination and more as a mechanistic response to conditions? Take, for instance, Toxoplasma gondii, known to cause rodents (to their mortal detriment) to lose their fear of cats, in whose stomachs the protozoan prefers to breed. In humans it's been linked, a bit more tenuously, to schizophrenia and, yes, suicide. A 2012 study of 45,000-some Danish mothers reported a "predictive association" between T. gondii infection and "self-directed violence." Far from causation, yes, but as T. gondii continues to spread, it might be helpful to get a clearer picture. CW
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