An evolutionary case for cannibalism.
While strolling last month through one of the dimly lit backrooms in a wing of the National Galleries of Scotland, my inner eye still tingling with thousands of Impressionistic afterimages, pudgy Rubensian cherubs, and gothic quadrangles, one irreverent painting leapt out at me in a very contemporary sort of way. It was part of an early-16th-century triptych showing what appeared to be a solemn, middle-aged clergyman in gilded ecclesiastical robes commanding three naked adolescent boys before him in a bathtub.
Now, I must say, my first thought on seeing this salacious image was that the Catholic Church has been a hebephilic haven for far longer than anyone realized. But my uneasiness was put to rest once I leaned in to read the caption, which stated that the Dutch artist Gerard David, a prolific religious iconographer based in Bruges, Belgium, was merely painting a scene of starvation cannibalism. Phew! What a relief it was only an innocent case of anthropophagy (the eating of human flesh by humans) and nothing more sinister than that. The boys had been killed by a butcher, you see, and their carcasses were salting in a makeshift vat awaiting ingestion by famished townspeople. Fortunately, that most notorious child-lover himself, St. Nicholas, just happened to be passing through town when he caught wind of the boy-eating scandal and resurrected the lads in the tub.
In any event, my time in Edinburgh offered plenty of food for thought on the subject of human meat. From the art gallery, my partner, Juan, and I galloped over to the Surgeons' Hall Museum, where we wandered through aisles packed floor-to-ceiling with pickled gangrenous feet, hairy severed arms of Industrial Age elderly women, trephined heads and a sundry of sickly genitals. Also on display was an elegant leather notebook, composed of a substance resembling cowhide but, in fact, made of the skin of the famous corpse supplier-cum-murderer William Burke.
All of this got me thinking about the logistics of cannibalism. The slick commercialization of the food industry has changed things dramatically, but there were, at one time, relatively frequent conditions—crop failures, habitat depletion, famine—in which cannibalism would have had lifesaving adaptive utility for our species. One pair of anthropologists, for example, actually crunched the numbers, concluding that the average human adult provides 66 pounds of edible food, including fat, connective tissue, muscle, organs, blood, and skin. Protein-rich blood clots and marrow are said (by the rare connoisseur) to be special treats. And indeed, at least one prominent evolutionary theorist, Lewis Petrinovich from the University of California, Riverside, has argued that cannibalism is a genuine biological adaptation common to all human beings—including those of you dry-heaving as you're reading this.
Anthropophagy routinely emerges, says Petrinovich, under predictable starvation conditions, and such examples of human cannibalism are not as rare as many people believe. "The point is that cannibalism is in the human behavioral repertoire," writes Petrinovich in his 2000 book The Cannibal Within:
… and probably is exhibited for a number of reasons—a common one being severe and chronic nutritional deprivation. A behavior might be exhibited only under extreme circumstances and still be part of our biological inheritance, and the fact that its course follows a systematic pattern argues against the hypothesis that it is psychotic in character.
Petrinovich wends his way through a human history littered with the gnawed-on bones of our cannibalized ancestors, revealing that—contrary to critiques arguing that man-eating is a myth conjured up by Westerners to demonize "primitives"—we really have been gobbling each other up for a very, very long time. We're just one of 1,300 species for which "intraspecific predation" has been observed. Among primates, cannibalism can usually be accounted for by nutritional and environmental stress, or it appears as a reproductive strategy in which mothers, for example, consume their unhealthy infants to make way for more viable offspring.
Pinpointing the specific factors that cause cannibalism is a rather difficult affair in the laboratory, mainly because of those pesky university ethics review boards. Still, an intrepid Japanese researcher shrugged off these considerations and induced cannibalism among a captive population of squirrel monkeys by feeding the pregnant females a low-protein diet. This led to a high rate of abortion and the mothers' devouring their aborted fetuses—a much-needed bolus of protein. Now imagine doing this same study with human beings under similar controlled laboratory conditions. Rather horrific, I should say, but that doesn't mean the findings wouldn't generalize to our own species. And don't get me started on the many ways that mammalian mommas feast on placental afterbirth. Some of our own prefer it with a dash of paprika, others as a spaghetti and "meatballs" dish.
But the fact that cannibalism is motivated in primates, including human beings, by starvation is precisely the point that Petrinovich is arguing. Where he differs from other evolutionary theorists, however, is in his assertion that anthropophagy represents a true adaptation in our species, just as cannibalism does for other animals. It is not simply an anomalous behavior found in a handful of depraved individuals. Such people do exist, to be sure—like this man who was so curious to know what his own flesh tasted like ("autocannibalism") that he … well, I'll let the clinical psychiatrists who examined him tell you in their own words:
After he cut the first toe, he first showed it to his flatmates before he ate it raw while he walked the streets. He chewed as much of the bone as possible and then spat it out. He recalls eating it 'for the experience' and that it was a 'once in a lifetime opportunity to eat human flesh'. He was excited by the shock value of doing so. The second toe was cooked in an oven before eating. In between cutting his toes he continued to work on renovating houses.
He's now safely medicated, a successful and happy builder, and presumably wearing special orthopedic shoes. But again, whereas cannibalism can certainly be deviant, in other cases it's perfectly normal—even healthy. Our close cousins the Neanderthals, essentially carnivorous predators, were driven to cannibalism at the end of the last glacial maximum in the face of dwindling numbers of large game animals. Osteoarchaeological research at a cave in southeast France yielded a bundle of roasted Neanderthal bones from about six individuals, haphazardly discarded bones that had been deliberately defleshed, disarticulated, and the marrow extracted.
Jesse Bering is the author of The Belief Instinct and Why Is the Penis Shaped Like That? (July 2012). He is a frequent contributor to Slate and writes the "Bering in Mind" column for scientificamerican.com. His next book will be on the curiously scandalous science of human sexuality. Follow him at www.jessebering.com, on Twitter @JesseBering, or try adding him on Facebook.
Oil painting "Zwei Legenden vom heiligen Nikolaus" by Gerald David, c. 1500. Courtesy of the National Gallery of Scotland. Illusration by Robert Neubecker.