Zombies as seen in the 2004 film Shaun of the Dead
However, the zombie of western popular culture is an entirely different entity from that of the magico-religious ritual of the Haitian and West African Vodoun religions of which it is based off of. The earliest traveller’s accounts of the zombification ritual fascinated outsider observers, such as William Seabrook’s (admittedly sensationalized) depictions of his travels to rural Haiti in his 1929 novel The Magic Island. What led credibility to the zombie phenomenon in the eyes of outside observers was not just that stories of people falling victim to Vodoun priests and sorcerors were common among the rural peasantry, but that accounts of people seemingly being resurrected from the dead were also found in more reliable documentation by western-trained physicians. A number of cases exist where someone was documented to have experienced a rapid decline in health and passed away, been interred, and then appearing some time later and identified by friends and relatives as none other than the one whom was declared deceased by a trained doctor (See Wade Davis’s 1988 account of his work on the Vodoun zombification phenomenon Passage of Darkness: The Ethnobiology of the Haitian Zombie).
It was not until around the 1980s with the work of ethnobiologists such as Wade Davis was a scientifically plausible explanation of the Haitian zombie phenomenon been put forth. Haitians recognize two forms of “zombie”. One is a spirit that has been sold to or captured by a Vodoun sorceror. The other being a victim of Vodoun sorcery who has been raised from the grave in a comatose state to work the land of the sorcerer as a will-less slave. This second concept of a zombie is closer to the walking dead of the zombie in western pop culture.
For a Vodoun sorceror to create a zombie, a complex ritual involving deep botanical, zoological, and religious knowledge must be performed. Through application of a carefully prepared poison consisting of plants containing pharmacologically active chemicals such as Albizia lebbeck, Mucuna pruriens, and Trichilia hirta, the tetrodotoxin containing porcupine fish (Diodon spp.) or puffer fish (Sphoeroides spp.), the poisonous and possibly hallucinogenic toad Bufo marinus, human remains such as finely ground bones, or other ingredients with pharmacological or magico-religious significance, a comatose and death-like state can be created in the victim. After the victim is pronounced dead and buried, the sorcerer exhumes him under the cover night and administers another carefully prepared antidote to wake the victim and together with an elaborate and surely terrifying ritual is able to induce in the victim the state of zombification. The zombie state can then be reversed through a variety of means, such as the death of the sorceror or exposure to substances such as table salt.
A Vodoun priest or houngan. Source
To the Haitians, the fear associated with zombies is a fear of becoming one rather than fear of being attacked or killed by one. Zombification is used by Vodoun sorcerors as a way to police the community, where victims are not chosen at random, but rather have offended their communities in some way or whose zombification has been paid for by a victim of a malicious act of theirs. The Haitian zombie ritual, aside from deliberate poisoning with a mixture of poisonous parts of plants and animals, is entirely non-violent and more magic or religious in nature.
However, when the western media took up the zombie concept, it turned it into a violent creature of its own making, with little left in common with its Haitian and West African Vodoun ancestors. Indeed the portrayal of the “Voodoo” religion in western popular culture takes many liberties with regards to the actual beliefs of its practitioners. Entirely western concepts such as “voodoo dolls”, usually used for violent and nefarious purposes, are creations of our media and have little in common with actual Vodoun practices. The violent and somewhat demonic portrayal of zombies and the Vodoun religion in western media surely has affected the common perception of the practitioners of the religion, if they are aware of the roots of the zombie concept at all. It certainly says something about the nature of the American psyche that a violent portrayal of the zombie is seen as more fascinating than a more realistic notion grounded in its roots as an pharmacological and religious phenomenon.
Zombies in the natural world?
Zombies can be created by a wide variety of means in western media compared to the fairly specific methods for creating a zombie in Vodoun ritual; for example, by raising the dead by occult rituals or by biological agents such as an infectious virus or parasite that takes control of the victims mind much like the fungus Cordyceps spp affects its insect hosts. Many consider a creature a zombie if and only if it has been raised from the dead. Zombies created by biological agents are typically referred to otherwise, such as the "infected" of the Left 4 Dead video game series, which makes no use of the word zombie in its canon.