— Author unknown
Cannibalism makes perfect evolutionary sense. If a population of spiders has an abundance of males from which a female can choose, then cannibalizing a few of them may serve to increase Charlotte’s overall fitness by increasing the odds that she can raise a new batch of spiderlings. On the other hand (and in spiders there are eight of these to choose from), in a population where males aren’t plentiful or where the sexes cross paths infrequently, cannibalizing males would likely have a negative impact on a female’s overall fitness by decreasing her mating opportunities. As a zoologist, I find this kind of dichotomy pleasing, since it’s logical and appears to be more or less predictable in occurrence. In nature, as far as cannibalism is concerned, I’ve found no gray areas, no guilt, and no deception. There is only a fascinating variety of innocent—though often gory—responses to an almost equally variable set of environmental conditions: too many kids, not enough space, too many males, not enough food. The real complexity and the uncertainty didn’t kick in until I shimmied out farther onto our own branch of the evolutionary tree. It was here that I found cannibalism painted in equal shades of red and gray.
Sigmund Freud believed that in humans, atavistic urges like cannibalism and incest are hidden below a veneer of culturally imposed taboos, and that the suppression of such forbidden behaviors signaled the birth of modern human society. This is a compelling explanation, but it’s one that likely requires some serious tweaking.
Compared to other groups such as insects and fishes, cannibalism occurs less frequently in mammals and even less frequently in our closest relatives, the primates—where most examples appear to be either stress-related or due to a lack of alternative forms of nutrition. Though we humans do share some of our genetic makeup with fish, reptiles, and birds, we’ve evolved along a path where cultural or societal rules influence our behavior to an extent unseen in nature. Freud believed that these rules and the associated taboos prevent us from harkening back to our guilt-free and often violent animal past. Similarly, my studies have led me to conclude that the rules we’ve imposed in the West regarding cannibalism serve as constraints to behavior that might otherwise be deemed acceptable if we were looking at protein-starved Mormon crickets instead of indigenous Brazilians consuming their unburied dead.
There is a considerable body of evidence that cultures that were never exposed to these taboos (like Homo antecessor) or encountered them only relatively recently (the Chinese and the Fore of New Guinea) had no such problems undertaking a range of cannibalism-related behaviors as they developed their own sets of rules and rituals. Much to our Western dismay, some of these cultural mores extolled the virtues of cannibalism as an honor bestowed upon a deceased relative or a slain foe, or as a respectful way to treat a gravely ill parent. But even in societies where cannibalism might once have been a perfectly acceptable practice, given the pervasive influence of Western culture across the world, it’s unlikely that ritual cannibalism currently exists, even on a small scale.
It’s also likely that Freud would have called upon long-hidden impulses to explain our titillation with all things violent, gruesome, and forbidden. But although it’s unclear to me the extent to which atavistic urges are involved, there is no doubt that we are, and seemingly have always been, fascinated by cannibalism. We need look no further than the popularity of novels like Cormac McCarthy’s The Road (with its depiction of post-apocalyptic cannibalism), or even our obsession with vampires and zombies. A long list of popular films might begin with The Night of the Living Dead and its cinematic progeny, and according to Variety, 17.29 million viewers helped turn The Walking Dead’s season five premiere into the most watched cable TV show of all time.
Our language is filled with cannibal references: a woman who uses men for sex is a man-eater, while in the 1920s and 1930s a cannibal was “an older homosexual tramp who traveled with a young boy.” To “eat someone” is a popular term for performing oral sex.