The ethnobiology of voodoo zombification

The word "zombie" usually brings to mind the creatures depicted in numerous horror films - the mindless, rotting "living dead" who shuffle with their arms stretched out in front of them, devouring the flesh of their victims.   

Zombies feature widely in popular culture, but the idea of the zombie originates in the Vodun religion. Popularly known as voodoo, this religion has been misrepresented and sensationalized, particularly in Hollywood films, according to which its followers practice bizarre rituals involving voodoo dolls and cannibalism.

In reality, Vodun is a complex belief system that is practiced by around 60 million people worldwide. Vodun was recognized as the official religion of Benin in 1996, and is the main religion in Haiti. It is also practiced in the Dominican Republic, Ghana and in the larger cities of the American Deep South, such as New Orleans.

In Haiti, the zombie is an accepted part of the culture, and up to a thousand new cases of zombification are reported every year. However, exactly how sorcerers zombify their victims remains open to debate. So, fascinating as it is, zombification is an ultimately confusing phenomenon.

Vodun can be traced back to the Yoruba peoples, who lived in parts of the countries that today are called Benin, Nigeria and Togo. During the 18th Century, the Yoruba were enslaved by French colonialists and shipped to the plantations on the Caribbean island of Hispaniola. The French tried to proselytize the slaves to Roman Catholicism, but the slaves continued to secretly practice their own religion. Modern Vodun, therefore, contains elements of Catholicism.

In Haiti, zombification is considered as murder, even though the victim remains alive. Article 246 of the Haitian penal code states:

It shall also be qualified as attempted murder the employment which may be made against any person of substances which, without causing actual death, produce a lethargic coma more or less prolonged. If, after the person had been buried, the act shall be considered murder no matter what result follows.

Haitian clergy attribute the creation of zombies to sorcery. The Vodun religion makes a distinction between the corps cadavre (the physical body), the gwo-bon anj (the animating principle) and the ti-bon anj  (agency, awareness and memory). When zombifying someone, the Vodun sorcerer (or bokur) extracts the ti-bon anj of the victim, and retains it in an earthenware jar (where it is then referred to as zombie astral).

Haitian doctors, on the other hand, consider zombification to be a result of poisoning, and there are reports that sorcerers use a white powder called coupe poudre to zombify their victims. In the early 1980s, Wade Davis, an anthropologist and ethnobotanist who was then working at Harvard University, travelled to Haiti in order to determine the ingredients of the coupe poudre. He interviewed a number of sorcerers and collected 8 samples of the zombie powder from 4 different regions of the country.

Upon analysis of the powders, Davis found that 7 of them shared a number of ingredients, including  toxins produced by cane toad (Bufo marinus, left) and an irritant produced by a hyla tree frog (Osteopilus dominicensis). One of the samples also contained trace amounts of tetrodotoxin, a potent neurotoxin produced by various marine organisms, most notably the pufferfish (below right). 

Davis published his findings, and his hypothesis of how zombification is performed, in two books, entitled The Serpent and the Rainbow  and Passage of Darkness: The Ethnobiology of the Haitian Zombie (the first of which was made into a film by director Wes Craven).

Davis hypothesized that the main ingredient of the coupe poudre was tetrodotoxin, ingestion of which usually causes death by paralysis. In sub-lethal doses, however, it causes a significant reduction in heart rate and metabolic activity, and puts one into a state in which they are completely paralysed but fully conscious.

(In Japan, the pufferfish Fugu rubripes is considered to be a delicacy. Tetrodotoxin is produced in the liver and ovaries, and chefs need special training in order to prepare the fish for human consumption. Every year, there are a small number of Fugu-related deaths; less frequently, there are reports of people being buried alive after going into a deep suspended coma following tetrodotoxin poisoning.)  

According to Davis, the irritant contained in the powder causes small wounds on the skin surface, through which the tetrodotoxin enters the bloodstream. The victim is pronounced dead, and buried alive. A few days later, the sorcerer returns to the burial site and disinters the "body".

The sorcerer then administers another cocktail of drugs that leaves the victim in a permanent state of delirium and disorientation. This second powder is thought to contain atropine and scopolamine, toxic and dissociative hallucinogenic compounds derived from the plants Datura stramonium (left) and Datura metel (both of which are known in Haiti as the "zombie cucumber").

Davis also put forward a reason why Haitian sorcerers perform zombification: it was a form of punishment for those who violated the laws of the clandestine Bizango societies formed in the mountains by escaped slaves (maroons).

Some see the hypothesis proposed by Davis as the only plausible explanation for zombification. Others, however, are critical of Davis' methods, and sceptical of his findings. It has been argued, for example, that the coupe poudre samples obtained by Davis did not contain sufficient amounts of tetrodotoxin to have any effect on humans. 

In response, Davis says that the powders were made by trial and error and not according to an exact formula, so that some would contain too little tetrodotoxin and have no effect, others would contain too much and kill the victim, and yet others would contain just the right amount and have the desired effect.

Davis also stressed that the zombie powder is just one requirement for zombification. Equally important, he says, is the victim's expectations of the effects of the powder, which have been learned through socialization. (This may be why zombification has never been reported in Japan.) 

Other researchers have proposed alternative explanations for the phenomenon. Professor Roland Littlewood of the Departments of Anthropology and Psychiatry at UCL, and Chavannes Douyon, a doctor at  the Polyclinique Medica in the Haitian capital Port-au-Prince, carried out case studies on three reportedly zombified people, and published their findings in The Lancet in 1997.

Here, Littlewood and Douyon describe the behaviour of one of their cases:

WD is a slightly built man, constantly scowling...He spent most of his time sitting or lying in a characteristic position, lower limbs to the left, upper limbs to the right, rarely speaking spontaneously and only in single words which were normal in form and content. He could not describe his period of burial or enslavement but agreed he malad (ill) and a zombi. He could be persuaded to walk with normal posture and gait, steadily but slowly...His eyes scanned around him with clear intent, his hands picking aimlessly at his nails or at the ground, and he avoided eye contact. 

This case was given a presumptive diagnosis of catatonic schizophrenia; the second was diagnosed as having an "organic brain syndrome and epilepsy consistent with a period of anoxia"; and the third was assumed to be simply a case of mistaken identity.

Littlewood and Douyon also interviewed two sorcerers for their study. Both recognized a puffer fish and a branch of a plant presented to them by the researchers as coupe poudre ingredients, and both gave the names of other plant and animal ingredients similar to those described by Davis. (The plant presented by the researchers, Hippomane mancinella, or manchineel, also known as the zombie apple, is used by sorcerers for topical application of the coupe poudre.)

It is likely, therefore that there is no single explanation for zombification. Mental illness, brain damage, learning diabilities, fetal alcohol syndrome or drugs, or a combination of these, all seem to be plausible explanations for the phenomenon.

And then there is Haiti's turbulent political history. Francois 'Papa Doc' Duvalier, for example, exploited the superstitions of his people, so that the huge number of abductions and murders - some estimate that as many as 30,000 were killed - were shrouded in the mysteries of zombification and other Vodun practices. Duvalier's paramilitary security service, the tonton macoutes, was also rumoured to consist of zombies who would carry out his every command. A better understanding of zombification would require consideration of all these factors.

Reference:

Littlewood, R. & Douyon, C. (1997). Clinical findings in three cases of zombification. The Lancet 350: 1094-96. [Full text]