Cannibalism is Common in the Animal Kingdom – Here's Why for Humans it's the Ultimate Taboo | Opinion

Vulnerable spadefoot tadpoles eat their smaller competitors to speed towards toadhood as quickly as possible. Gulls and pelicans are among bird species that eat hatchlings for food or to prevent the spread of disease. In insect species such as the praying mantis or the Australian redback spider, males offer their bodies as a final gift to females after mating.

It's more common than you'd think in mammals too. Many rodent mothers may eat some of their young if they're sick, dead, or too numerous to feed. Bears and lions kill and eat the offspring of adult females to make them more receptive to mating. Chimpanzees sometimes cannibalize unlucky rivals, usually infants, seemingly for the mere opportunity of some extra protein.



Participants read that this occurred in a culture that permitted the act, that the act was meant to honour the deceased, and that the flesh was cooked so that there was no chance of disease. Despite this careful description, about half of the participants still insisted that the act was invariably wrong.

praying mantis
Female praying mantises are known to bite off the heads of their sexual partners after mating. JACK GUEZ/AFP/Getty Images

Even in the starkest of situations, the act of eating another human's flesh remains almost beyond contemplation. Survivors of the famous 1972 Andes plane crash waited until near starvation before succumbing to reason and eating those who had already died.

One survivor, Roberto Canessa, felt that to eat his fellow passengers would be "stealing their souls" and descending towards "ultimate indignity"—despite recalling that in the aftermath of the crash, he like many others had declared that he would be glad for his body to aid the communal survival mission.

Categorical disgust

The tragic anecdote above illuminates why humans are the exception to the animal cannibal rule. Our capacity to represent the personalities of the living and the departed is unparalleled. This deep connection between personhood and flesh can mean that careful reasoning in certain situations over the merits of cannibalism is overridden by our feelings of repulsion and disgust.

So why our disgust for human flesh but not that of other animals? Philosopher William Irvine has us imagine a ranch that raises plump babies for human consumption, much like we fatten and slaughter cattle for beef. Irvine suggests that the same arguments we apply to justify the killing of cows also apply to babies. For example, they wouldn't protest, and they're not capable of rational thought.

Although Irvine is not seriously advocating eating babies, the scenario is useful for illuminating our bias when considering the ethics of cannibalism. From a young age, we tend to think about categories, such as humans or cows, as having an underlying reality or "essence" that cannot be observed directly but that gives a thing its fundamental identity. For example, humans are intelligent and rational thinkers, we have personalities and a desire to live, and we form bonds with each other.

This psychological essentialism is a useful shortcut to guide our expectations and judgements about members of the category—but it doesn't work so well when the typical qualities of that category don't apply, for example upon death. This is why consensual post-mortem cannibalism is still met with such disgust. Even if we can bring ourselves to deem it morally acceptable, we can't silence our thoughts about the person it came from.

The way we interact with animals shapes the way we categorize them. Research shows that the more we think of animals as having human properties—that is, as being "like us"—the more we tend to think they're gross to eat.

Adapting to the unfamiliar

Though accusations of cannibalism have often been falsely made to demonize groups, it isn't absent from human history. The Fore people of Papua New Guinea were reported to have participated in funerary cannibalism, believing it better that the body was eaten by people who loved the deceased than by worms and maggots. Parts of mummies were eaten for medicinal purposes in post-Renaissance Europe.



For now, we're as happy as you are to continue accepting the "wisdom of repugnance": human flesh, despite its biochemical similarities to that of other mammals, shall remain firmly off limits.

Jared Piazza is a lecturer in social psychology at Lancaster University, U.K.; Neil McLatchie is a lecturer in psychology at Lancaster University.

This article is republished from The Conversation under a Creative Commons license. Read the original article. Views expressed in this article are the authors' own.

CORRECTION: The headline of this article has been updated to match the one used in the original article published in The Conversation.

Cannibalism is Common in the Animal Kingdom – Here's Why for Humans it's the Ultimate Taboo | Opinion | Opinion