How Zombies Work

Davis traveled to Haiti at the request of Dr. Nathan S. Kline, who theorized that a drug was responsible for Narcisse's experiences as a zombie. Since such a drug could have medical uses, particularly in the field of anesthesiology, Kline hoped to gather samples, analyze them and determine how they worked.

Davis learned that Haitians who believed in zombies believed that a bokor's sorcery -- not a poison or a drug -- created them. According to local lore, a bokor captures a victim's ti bon ange, or the part of the soul directly connected to an individual, to create a zombie. But during his research, Davis discovered that the bokor used complex powders, made from dried and ground plants and animals, in their rituals.

Davis collected eight samples of this zombie powder in four regions of Haiti. Their ingredients were not identical, but seven of the eight samples had four ingredients in common:

In addition, the powders contained other plant and animal ingredients, like lizards and spiders, which would be likely to irritate the skin. Some even included ground glass.

The use of puffer fish intrigued Davis. Tetrodotoxin causes paralysis and death, and victims of tetrodotoxin poisoning often remain conscious until just before death. The paralysis prevents them from reacting to stimuli -- much like what Clairvius Narcisse described about his own death. Doctors have also documented cases in which people ingested tetrodotoxin and appeared dead but eventually made a complete recovery.

Davis theorized that the powder, applied topically, created irritation and breaks in the victim's skin. The tetrodotoxin could then pass into the bloodstream, paralyzing the victim and causing him to appear dead. The family would bury the victim, and the bokor would remove the body from the grave. If all had gone well, the poison would wear off and the victim would believe himself to be a zombie.

While Davis's theory is promising, it does have some holes. Next, we'll look at the controversy surrounding Davis's research.

At first glance, Davis's research seems promising. Tetrodotoxin definitely causes paralysis and death, and researchers have documented cases in which people have recovered from near-fatal tetrodotoxin poisoning. Some of the samples Davis brought back to the United States also produced dramatic results when applied to the shaved skin of rats and a rhesus monkey. The subjects became lethargic and then immobile, but they eventually recovered completely.

Other researchers, however, have raised questions about the legitimacy of Davis's research and the actual components of the samples he brought back from Haiti. Scientists have:

A lot of people view Davis's work as the only possible explanation for the Haitian zombie phenomenon. Others dismiss it as unscientific or even fraudulent. You can learn more about the controversies regarding Haitian zombies and Davis's research in the April 15, 1988 issue of the journal Science or the October 11, 1997 issue of The Lancet.

Haitian zombies have been the inspiration for movies, books and video games. Next, we'll look at portrayals of zombies in popular culture.

Although zombies appeared in movies as early as 1919 [ref], many people credit George A. Romero with setting the standard for modern zombies. In the classic movie "Night of the Living Dead," Romero portrayed zombies as slow-moving, flesh-eating corpses, reanimated by radiation from a satellite returning from Venus. The radiation affected the recent, unburied dead, and the resulting zombies were invulnerable until someone destroyed their brains or separated their heads from their bodies. In "Night of the Living Dead," zombies were neither intelligent nor self-aware. They had a very limited use of tools, mostly confined to using blunt objects as cudgels. In Romero's later work, zombies became somewhat capable of thought, and in some cases self-aware. They still generally moved slowly and had minimal intelligence.

Many movies and video games have used Romero's concept of zombies. For the most part, zombies are:

In some portrayals, zombism is contagious, and people bitten by zombies become zombies themselves. In others, people die from the bite and are reanimated by the same force that created the other zombies. In general, this continual spread of zombies leads to a zombie plague in which the undead vastly outnumber living humans.

Some recent zombie movies, like "Shaun of the Dead," adhere faithfully to the Romero zombie conventions and make frequent references to his work. Others depict faster, more intelligent zombies. Films like "28 Days Later" keep the basic structure of a zombie film but do not portray actual zombies. (In "28 Days Later," people are infected with a virus that takes effect in seconds -- they don't actually die until they eventually starve.) A few recent movies and games throw all these conventions aside, presenting zombies that move quickly and can think for themselves, much to the chagrin of zombie purists.

Next, we'll review how to defend yourself from a zombie attack.

Whether featuring traditional, shambling zombies or a newer, smarter breed, most movies and games agree on how to survive a zombie attack:

Also, avoid common mistakes like:

Follow the links below for lots more information about Haiti, voodoo, zombies and related topics.