Monday, February 05, 2007

Why Do Zombies Eat Brains, Anyway?

A zombie is purportedly a dead person whose body has been re-animated... [Other] more macabre versions of zombies have become a staple of modern horror fiction, where they are brought back from the dead by supernatural or scientific means, and eat the flesh of the living.

The notion of zombies has been pretty here-and-there for me as a writer. On one hand, it's a powerful tool that can denote a substantial atmosphere of dread when used properly; On the other hand, it's become a generally overused element that doesn't immediately scare audiences as much as give them the impression of an uncreative concept. Much like the zombies themselves, they can either help or seriously hurt one's professional reputation.

I won't go into a detailed history and analysis of zombies here. To be honest, I located an astounding number of established references while surfing the web this morning -- some satirical, some questionable -- and I'm certain that a little bit of legwork should answer all the background questions you have about the undead phenomenon. At the very least, there's already a link to the Wikipedia entry up there, just underneath the title of this post.

No matter how many sites I visited, however, this morning's research failed to provide a concrete answer to the question that had been bugging me since last night: Why do zombies eat brains, anyway?

Most of the references I visited tended to agree upon a single zombie "stereotype" in modern media and entertainment. For one, the undead are usually re-animated corpses, or victims of a virus or condition that manifests in a similar appearance. Usually being of a non-cognitive, nerveless state, these stereotypical zombies invariably shamble around at a less-than-optimal speed. They prove resistant to environmental threats, physical pain or the dislocation of limbs. They may either be controlled by a single external intelligence, or may retain a primitive pseudo-bestial instinct per individual. They are particularly hostile to the presence of living beings, to the point of immediately attacking and killing any perceived targets.

That, and zombies eat living flesh. There's a bit of a logical disconnect here, to be honest: I suppose that every, er, "animate" being should have to have something to eat, yes... but modern media seems to accept the background notion that zombies are just as perfectly willing to eat beef shanks or pork slices when they clearly aren't willing to feed on each other. It's more a minor contradiction, though, than anything else.

What I don't understand, though, is why we play host to the perception that zombies eat brains so easily. It doesn't even exist as a fringe understanding, mind you -- despite the fact that very few comprehensive zombie references on the Net mention the undead's tendency for brains, there seem to be plenty of incidences of the association floating around. Do a search for "eating brains" on Google, for example, and you'll find that the vast majority of your results most definitely won't be centered around Fear Factor.

I suspect that the first vestiges of the zombie-brains association came about from Dan O'Bannon's Return of the Living Dead, the first movie to reference the neural delicacy. Return of the Living Dead, however, merely explained that human brains "ease the pain" of one's undead state, and includes no specifics on exactly how or why this happens to be the case. In any event, this explanation didn't quite carry over to the media-influenced public: We can put together a mental connection between zombies and brains, but for the most part, we don't know why this connection exists. In short, we simply don't know why we could possibly think that zombies eat brains.

Wil McCarthy's "Lab Notes" column at actually offers an alternative explanation, albeit one that was mentioned only in passing:
Now, zombies are clearly capable of breathing, because they can groan, screech and sometimes even speak, so presumably there'd be some oxygen coursing through the system... However... zombies have no heartbeat and can survive indefinitely underwater, and... they can continue attacking even if all their blood is drained out. This implies a very robust anaerobic metabolism, probably powered by the fermentation of fat. (This would also explain the particular hunger for brains, which are 60 percent fat by volume.)

To state that zombies eat brains for their proportion in fat is still kind of debatable, though: While it does also explain why living flesh is also a distinct part of their menu (they could be after all the fat deposits, after all), it raises the possibility of other, more convenient sources of, er, nourishment. Why don't they raid supermarkets, butcher shops and liposuction clinics, then? If their senses are heightened enough to sniff out the concentrated fat in a human body, then why not do the same for presumably larger concentrations of the stuff in a single convenient place?

A flurry of responses to the same question (asked by bryanboyer) in the Ask Metafilter ("AskMe") offer up a bunch of scientific hypotheses. These range from the physiological (Brains hold both glial cells and and a high cholesterol content, which may help replicate lost brain cells and maintain cell membrane consistency, respectively) to the psychological (It's an instinctive-agressive action for the undead to regain their own lost minds) and the sociological (Because dead bodies without brains cannot exist as zombies, the practice of eating brains helps regulate zombie populations). While these proposed answers are both extremely interesting and well thought-out at the same time, they don't directly reference the current scenario we're looking at. We're looking for a reasonable explanation that not only points out why zombies eat brains, after all, but why they would hunger specifically for brains, and why they adopt a ravenous, highly aggressive stance in doing so. Perhaps the answer actually lies in some combination of these proposals.

Then again, it could simply be that zombies don't necessarily go for brains at all (despite certain media-based attempts at convincing us otherwise), and that the zombies-brains connection is just a logical fallacy that sticks to our heads without explanation. It's possible, after all, that we retain this bit of knowledge simply for its remarkability without delving too deeply into its background. In that way, it's much like any chain letter or urban legend that we encounter: We've all probably heard that one should never consume both Coca-Cola and Pop Rocks at the same time for fear of death, for example, but we never have any concrete evidence as to why this is so. We just remember a Coke-Pop Rocks connection and think little more of it.

That, and I suppose that zombies will always be zombies. They may or may not have reasons for the things they do; It's not as though we can expect them to be about as cognitive as normal human beings, after all. Otherwise they might not even be ambushing people and attempting to eat their, umm... er... brains in the first place.

With that, I'll leave this question up in the air. Even if we do manage to come up with an explanation that covers all the bases, I suppose, we'd be left with no guarantee that it'll justify the opinions of the zombie-oriented public out there. People just seem to immediately believe that zombies favor brains for some reason; At this point, I'll say that it's altogether possible that we have no such reason at all to explain the matter.


Dominique said...

Hmmm...maybe it's just because brains are yummy?

Sean said...

Dominique: Nevertheless, the human brain would have to be incredibly, unbelievably, orgasm-inducingly delicious in order for any run-of-the-mill zombie to pursue it as hotly as they do.

Mmmmm... brains. :)

Anonymous said...

Don't knock it till you've tried it.

--Hannibal Lecter

Sean said...

Anonymous: Oooooh... Ray Liotta. :)

Jake said...

It really depends on which type of zombies we're talking about. A lot of zombies don’t eat brains, or at least don’t eat brains exclusively. It’s mainly zombies that have been reanimated by toxic chemical spills that are in need of brains. See, chemical reanimation affects a corpse by combining the toxic agents with the natural byproducts of decay. This reaction creates an altered chemical that becomes intrinsic to the corpse. The new chemicals react in the nervous system of the corpse to simulate normal body functions such as locomotion, sensory data processing, and, in limited cases, speech. Of course, the simulation is not perfect, hence the zombies’ characteristic herky-jerky movements, slow reactions, and garbled moaning speech. The brain, or what is left of it, is stimulated in such a way that relatively intelligent zombies are possible and common. Chemical zombies are also harder to kill because they do not require normal brain function to move and cannot be stopped simply by damaging the brain. The chemical reaction can take place in any neuron, so if there is any nervous material left, the zombie (or zombie pieces) will continue to attack. “Why do they attack?” you might ask. Well, the chemical reaction taking place in the body causes extreme pain and the violently stimulated nervous system amplifies this pain. Zombies are able to alleviate this pain by, you guessed it, eating brains. This is simply because the chemicals will react with any nervous material internal to the body, including the ingested brains. This causes a temporary lessening of the chemical attack on the body of the zombie and a corresponding alleviation of the extreme pain. In a rather surprising display of meme propagation among the undead and in what limited capacity that they are able to, the zombies almost universally think of this and have been known to refer to it as the “pain of being dead.”

Sean said...

Jake: I feel that the explanation still involves a bit of a stretch, though: You'd need a hypothetical combination of chemical agents to interact with a corresponding combination of similar chemicals from a human body (living or dead). While it's possible, I fear that the range of chemical agents (and their corresponding amounts) would make the chances of reanimation by toxic exposure quite remote. That said, it is within the realm of possibility, and is somewhat plausible.

I find that this does raise another interesting note, though: Technically, this implies that zombies cannot physically propagate; that getting our brains devoured by zombies won't turn us into zombies ourselves. Apart from the victims of zombies not having any remaining brains to speak of, it would take similar exposure to the same chemicals to actually cause the metamorphosis -- a transfer that cannot be induced from zombie to zombie, assuming that the aforementioned reactions have changed the original state of the chemical agents.

Anonymous said...

It angers me so much that just because I'm a zombie peple think I eat brains. We don't eat brains! It's just some sick rumor that got started by all the crappy B moives.

Sean said...

Anonymous: To be fair, I did mention that:

I suspect that the first vestiges of the zombie-brains association came about from Dan O'Bannon's Return of the Living Dead, the first movie to reference the neural delicacy.

The assumption that zombies eat brains could be nothing but a case of media influence. It does still leave the question of exactly what constitutes a proper zombie diet, but that would be outside the scope of this discussion.

Brian Hardin II said...

Sorry to bring up an older topic but...

Zombies eat brains because they cannot sleep. Humans sleep and therefore dream. Because zombies cannot sleep they are unable to dream.

Therefore zombies go for brains to eat the dreams.

Note, this does not explain why they do not go after other animals for as the quote by Shirley Jackson;
"No live organism can continue for long to exist sanely under conditions of absolute reality;
even larks and catydids are supposed, by some, to dream."

Stay Scary!

-Brian Hardin II

Sean said...

I'm amazed that this post is still getting responses.

Brian: Hi, Brian. I have to admit that I didn't consider the "dreams" angle. The mere idea makes for a great story seed... and I'm not surprised that it possibly comes from Shirley Jackson (author of "The Lottery", one of the most eyebrow-raising short stories I've ever read, in case anyone else is reading this).

However, I'm not convinced that it makes for a good physical explanation. Is it possible to dream by consuming the living brains of beings who can presumably do so? I always assumed that dreams were a product of sleep (and not the brain itself) - ergo, one can't gain access to dreams by eating the brain.

Further... wouldn't the zombies eventually become aware of this? I mean, a zombie who's had a taste of a couple of brains would quickly realize that they didn't get any dreams out of the whole deal, and would probably stip pursuing the darn things. Yet a zombie who manages to consume a couple of brains will, presumably, still hunger for more. There's got to be something else to the desire for cranial paté.

On the other hand, I'm making a lot of assumptions here. I'm assuming that you can't eat dreams by eating brains, I'm assuming that zombies are logical to a certain degree, and I'm assuming that at least some zombies will "live" long enough to consume more than a few of their odd meals. This could be a good explanation right here, but I'm not sure if it's a better explanation than the other options we have so far.