Science: Stand Back! I’m going to try…..Zombies?

by Shara E. on October 25, 2012

It’s that time of year again: stores are flooded with images of ghouls, goblins, vampires and skeletons; houses are covered with fake spider webs; scary movies are all you can find on the television; and I’m pretty sure every parent in the country is trying to figure out their strategy for making sure their kids don’t consume 10 pounds of sugar in one day. Yep. It’s almost Halloween! I adore this time of year. Really, I do, except for one minor problem; I am an absolute baby when it comes to scary movies and haunted houses. I slept with a light on for two weeks after I was tricked into watching Paranormal Activity, and (much as I love the show) I flat out refuse to watch The Walking Dead unless there is daylight outside.  I certainly won’t be winning any bravery awards when it comes to super-natural spookiness.

Source: EPhotography under Creative Commons

One way  I deal with my knee-jerk-run-screaming-for-the-hills reaction to said spookiness is to retreat to my ivory tower of science, and try to rationalize everything. If I can bring what I’m afraid of into the realm of science and medicine, I tend to be less easily scared by it.  In fact, it has become a game to try and find theoretically plausible explanations for monster myths and legends. Anything that can explain the signs and symptoms associated with a mythical condition. For example, werewolf legends could be based on people from hypertrichosis and vampires could have been inspired by porphyria or Xeroderma Pigmentosa.  Of all of these ‘games’ the best one is always zombies because I’m always tripping over new ways to explain the  listnessness, fever at onset resulting in mindlessness, awkward mobility, cannibalism and infection spread through biting. The most common explanation (and probably the real basis of zombie stories) is rabies, but there are some other crazy options out there to play with.

In short? Happy Halloween! Here’s some science to go along with that candy!

More on Rabies (and Zombies)
Rabies  is probably the primary source of zombie legends.  Humans have known about rabies for a long time: references to the disease have been found dating as far back as 2300 BC, both Homer and Aristotle mention it, the first major outbreak recorded was in 1271, and Louis Pasteur administered the first successful rabies vaccine in 1885.  The disease progression most clearly mirrors the ‘typical’ progression of a zombie-like illness as well, and the signs and symptoms following a infection are very similar in animals and humans.   As Esther Inglis-Arkell beautifully summarized:

Biting, fear of light, speechlessness, and the intense aggression that most zombie movies display all come from a single source; rabies. Take a look at the original “rage virus.”…Animals with rabies, although they can barely swallow water, have been seen to eat sticks and rocks. They also seem to undergo a compulsive need to bite. Scientists think that this is the disease trying, evolutionarily speaking, to strike out and get transmitted to a new host. This is the crux of the zombie mythology. A bite means a death of the self — loss of speech, coherence, lucidity, and ability to control aggressive impulses — and a rebirth as a silent, unresting zombie, endlessly driven to look for new people to bite.”   – The Virus that Inspired the Whole Zombie Genre.

While we can look at the signs and symptoms for rabies and match them up with typical zombie traits, is it really fun to let the explanation go so easily?  Nope, it’s not. So are there any other possible explanations for Zombification? Well, I’ve got a couple so far, with some potential mechanisms for our own non-rabies-related Zombie Apocalypse.

In May of 2012, a 31-year-old homeless man was killed by police after he had been caught eating the face of another man, and refused to back away when officers ordered him to stand down. This was one of several violent incidents in the United States, dating back to 2010, involving individuals who were under the influence of a class of drug called bath salts. Under the influence of bath salts (and sometimes other drugs) users had zombie-like, insane, and violent behaviors, often causing serious injuries to others as well as themselves.

These behaviors included cannibalism, growling, clawing and biting.

Bath salts refer to a class of drugs that contain synthetic cathinone and cathinone derivatives. Typically Bath Salts contain methylenedioxypyrovalerone (MDVP), mephedrone  or methylone.  All three chemicals can induce a high similar to methamphetamines or cocaine and were largely unregulated in the United States until late 2011.  Additionally, bath salts easily lend themselves to overdose; the drugs’ effect can be seen after ingesting as little as 3mg, but average doses are much higher (5-20) and some packages that were marketed contained over 500 mg.   In the event of overdose, psychosis, hallucinations, paranoid delusions and in some cases extremely violent behavior can occur. The similarities between the effects of these drugs and zombie-like behavior did not go unnoticed by the media.

Bath salts are not the first compound associated with zombie-like traits. In the early 1980 anthropologist and ethnobotanist Dr. Wade Davis carried out a two year “Zombie Project,” dedicated to discovering the causes behind Haitian Zombies. In his travels, Davis collected eight samples of “zombie powder” which was said to be used by bokors (sorcerers in vodou religion), who resurrected the dead and turned them into slaves.  Davis found that all but one of the powder samples shared the same four ingredients: tetrodotoxin, which is found in puffer fish; two species of toxic frogs; and human remains. The toxins from the frogs and tetrodotoxin are all known to produce symptoms similar to zombie behaviors including paralysis, inflammation, irritation and other neurotoxic effects.

So basically…..

Clip art from, Puffer Fish from Wikipedia Commons

Maybe the human remains were added for extra effect?

All in all, zombies provide a great playground for musings when it comes to pondering biological and chemical plausibilities for the supernatural. Particularly during Halloween, when there are zombie movies and horror stories everywhere. These musings also have, for me at least, the wonderful side effect of being at least slightly more willing to consider watching said zombie movies. Just keep in mind that there is not a single theory or remote plausibility that will get me to watch Paranormal Activity 2, 3 or 4.


Frank DeSanto October 26, 2012 at 10:59 am

Great fun, this!

Angela October 26, 2012 at 3:11 pm

Ha – very fitting to mention the infamous ‘bathsalts’! The have indeed been the stuff of zombie legends through the mass media. Thanks for the seasonal post (and the Haiti-potion inspired ‘zombie equation’!). My observation would be to be careful with specialist names such as hypertrichosis, porphyria, Xeroderma Pigmentosa or the chemical components of ‘bath salts’ that you mentioned. With the first set of terms, I would suggest that you just put a brief explanation in brackets, so that people don’t have to look stuff up on other sites. With the chemicals, the reverse might be more user friendly. Personally (other science communicators might disagree with me here), I’d mention that ‘bath salts’ contain chemicals that have similar effects (or are perhaps also found in substances similar) to cocaine etc. and link to a page which lists/explains the chemicals or drug, if possible. Some people might also want to know a bit about the history/origin of the drug (is it natural/synthetic? is it made in the US? is it popular?). Good places to check for good communication of chemical components (or for linking to), I find, are actually police websites/leaflets (my dad was a police detective, so I got inundated with this kind of information) and drug/prescription drug addiction/medical charities.

Shara E. October 29, 2012 at 10:30 am


Thank you so much for the feedback! I try to balance between too much info and not enough, sometimes it’s hard to find a good balance. re: the history of Bath Salts, they are a class of drug containing synthetic cathinones (actual cathinones come from a shrub called the Khat, and are regulated) were actually discovered in the 1920s, and more or less ignored until someone ‘rediscovered’ them in their garage lab somewhere. The entire class of drug seems to have more or less caught everyone by surprise in 2009-10. I didn’t want to delve too deeply into the matter since the issues were still a bit fresh, and frankly gruesome enough that i didn’t want to go into much depth, but i did want to give some info on them.
Again, thanks for the feedback!! I’ll definitely be thinking about it in the future 😀

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