One of my most popular posts by far is the one where I tried to explain (more than 3 years ago, wow!) why zombies eat brains. I still think it’s the most common question of people who are getting into the genre (or just trying to figure out why I’m so weird), and I still don’t really have any better guesses than I did when I wrote it back then.
But! You guys seem to have some really good ideas. So I wanted to revisit this question and go into some of the points you’ve raised.
Zoghrob (a surgeon!) pointed out:
There is a fact that I want to add. Brain tissue got substances called “Endorphins” & “Encephalins” which are morphine like substances, & are produced by the brain in cases of severe pain to ease it out, so when the mouse is between the teeth of the cat, suddenly it falls into a coma like state, due to these substances. This was mentioned briefly in 1985′s “return of living dead” when they tied up the half woman corpse & asked her why do they eat brains, she answered “it makes the pain go away”. Nice fact.
I LOVE this theory. (Let’s just ignore the fact that it originated in a movie where zombies were talking; you all know how I feel about that.) It would totally explain a) why zombies can’t feel pain, and b) why eating people – even people they love – is preferable to the alternative, which I’m assuming would be unbearable pain. I mean, I would imagine that having to feel yourself decomposing would not be pleasant. It might even help explain some of the other inhuman qualities of zombies – maybe they can’t communicate or use any complex motor skills because they’re in the equivalent of a coma.
We all know no zombie conversation would be complete without some good arguing – and you guys sure did point out all the holes I conveniently avoided in my first explanation. Let’s see if I can be more thorough this time.
Do they have vital signs and a metabolism? does eating help? what is the life expectancy of one sans bullet to the head?
I don’t think they have any vital signs except for some mild brain activity which keeps them functioning at the most basic level. In season 1 of the Walking Dead, the CDC shows a time-lapse video of a zombie victim turning during an MRI, and it shows the brain shutting down completely and then suddenly restarting a few hours later but with a tiny fraction of the activity that existed before the victim died. That seems about right to me. In terms of eating, again, I don’t think it sustains them the way eating keeps us alive. I think it serves some other purpose though – either giving them energy, keeping their minimal brain function going, or (as the doctor suggested, above) making the pain go away.
I spend a LOT of time wondering about the natural “life” expectancy of a zombie (no way to get around that oxymoron). If I had enough supplies, would I be able to hide out in my apartment and just let all the zombies die out? I haven’t come to a solid conclusion on this one because the experts seem to be divided 50/50 on it. Personally, I’m inclined to think that they will die out eventually. If not, then eating brains doesn’t serve any kind of preservation function, and that just doesn’t seem right. Anyway, the definitive answer comes as usual from The Zombie Survival Guide: a zombie will decompose completely (whether they eat or not, apparently) within 5 years.
Michele wanted to know:
Why is it zombies always seem to retain their teeth and vocal cords? Of course, it’s for dramatic effect – but you would think that someone would have come up with some “science” to add to the mythology.
That is a REALLY good question. I could definitely see this being explained as part of the effects of the zombie virus – maybe your teeth and throat are kept intact like certain parts of your brain while the rest of your body rots, since you need them to keep chomping on people. It is really weird that I’ve never seen a zombie in a movie without any teeth. (Actually, I’ve always wondered what it would be like for an old person without any teeth left to become a zombie – seems like a cop out to never address this question. Could they just claw a person open and suck out their innards to sustain themselves? Who knows!)