Outside the Forensic Box: A Tale of Lies and Lemmings

Evidence can be distorted by combinations of errors and deliberate falsehoods.

Reviewed by Hara Estroff Marano

Key points

• Evidence can be distorted by cognitive misinterpretations and by belief in deliberate falsehoods.
• Such distortions hamper criminal justice proceedings, but they also occur outside this realm.
• The two factors are especially powerful when they combine in any given investigation.
• Useful examples are seen in myths about animal behavior, especially tales of Arctic lemmings.

Evidence in court can be dramatically distorted by cognitive misinterpretation of observations (e.g., Sharps, 2022) and by beliefs, on the part of witnesses, in deliberately created falsehoods. But what happens when these two factors combine?

We frequently learn a great deal about the psychological processes involved in the criminal justice system from outside the forensic box, from examination of events in the world outside that system. In this instance, relevant information comes from a surprising source: myths about lemmings, rodents of the far north.

Lemmings are little furry mammals that sometimes swarm in great numbers in Arctic regions. They are apparently incredibly courageous, sometimes charging at much larger creatures in a rodent equivalent of the question, “Do you feel lucky, punk?” To which, a few seconds later, the Arctic fox at whom they charged responds with the foxy equivalent of “Pretty much, yeah,” as it picks lemming fur out of its teeth. They're brave, these lemmings, but, apparently, not very bright.

Many people believe that these rodents are so brave that, when they overpopulate, they migrate in vast numbers to the sea and suicidally leap in, freeing the tundra for the next generation of lemmings. This isn’t true, but it's astonishing how many people believe it.

An even better lemming myth: The brave little furballs can become so enraged that they actually explode.

It turns out that we can explain both myths. Lemmings sometimes really do move in great numbers, dispersing or migrating in search of better resources. The mass movements are frequently funneled along specific routes by local geographic features, and the routes often come up against bodies of water. When this happens, some of the lemmings crowded against the shore may fall in, or attempt to swim across, with or without success (e.g., MacDonald, 2001). Therefore, people in northern climes have seen lemmings falling into bodies of water and attempting to swim across them. Sometimes they don’t make it, which would seem to indicate accidental drowning rather than suicide. However, parsimony of explanation frequently takes second place to dramatic interest, and the lemming suicide myth seems to have originated on these somewhat shaky grounds.

What about the rage-based lemming explosions? Well, all sorts of Arctic predators eat lemmings, and the vast rodent dispersals are treated by the foxes and skuas and so forth essentially as a mobile meat market. Many predators are not exactly fastidious eaters, and you can find discarded, fuzzy, and fairly disgusting lumps of partially-eaten prey all over the place when many types of carnivores attack an overly abundant supply of meat. Any given semi-devoured ex-lemming may therefore look like a tiny grenade went off inside it; hence the probable origin of the explosion myth.

The Explosive Lemming Effect may be a simple eyewitness misinterpretation of what we see after the foxes and skuas finish their sanguineous dinner parties. Similar cognitive misinterpretations are ubiquitous in the eyewitness realm, in the criminal justice system, and everywhere else. But how, in contrast, did the Lemming Suicide Myth become so well-known?

It took a deliberate falsehood to create the suicide myth, to turn an occasional misinterpretation of quasi-aquatic lemmings into mass rodent martyrdom.

For the 1958 True-Life Adventure film “White Wilderness,” the filmmakers wanted to capture mass lemming suicides on film. The problem is that lemmings don't actually commit mass suicide. Also, there weren't any lemmings in the part of Canada where much of the filming went on.

So, the filmmakers apparently bought some lemmings from some Inuit children, who for completely unexplained reasons had some of the fuzzy little rodents in stock, and proceeded to work various special lemming effects using turntables, local bodies of water, and practically anything else they had to make their relatively small platoon of perfectly normal lemmings look like a Suicidal Rodent Horde. The film's narration suggests that the poor little furballs were compelled by an unreasoning “hysteria” to fling themselves into the sea for the good of Lemmingkind. This would, of course, have been a form of adaptation that makes no Darwinian sense whatsoever, but again, scientific parsimony frequently takes second place to dramatic interest. Anyway, to make their point and to stage the mass act of self-destruction, the filmmakers actually proceeded to fling their miniature horde of lemmings off a cliff into the Bow River, which in the film played the Arctic Ocean (e.g., Snopes.com, 2015).

History is effectively silent on exactly how the film crew did this. An older version of the story has them using push brooms, but this cannot be confirmed. If the action was actually mano-a-lemming, one assumes that the lemming-flingers were at least wearing thick gloves—the brave little rodents have brave little teeth—but we will probably never know exactly how the lemming flinging in question took place. The one thing on which history agrees is that a number of lemmings were in fact flung.

The movie was a great success. Huge numbers of parents took huge numbers of children to the theaters to learn about the natural world, and the children were treated to an astonishing exhibition of the results of completely unnatural lemming-flinging.

The film worked so well that this arcane myth, concerning a minuscule mammal of remote regions, a creature of which most people have no personal experience and very little awareness, has effectively permeated all corners of the Western world.

Cognitive distortions and deliberate falsehoods can influence our beliefs, inside the courtroom and in the wider world outside it. However, the lesson of the Incredible Cinematic Lemming-Flinging Effect is that when these two factors combine, they can be devastatingly effective in producing false beliefs.

This can be deplored in the artificial world of the cinema. But in the very real world of criminal investigation and the courtroom, this combinatorial effect may result in vastly more damaging human consequences.