Fajardo Aceves Jesus Manuel, from Mexico, has congenital hypertrichosis.

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Real Werewolves

Most people have heard of the witch hunts of the 16th century. Less well known are the werewolf hunts that happened in the same time period. A common belief was that werewolves turned their skin inside out to return to human form, so one interrogation practice involved cutting and pulling back a person's skin to see if there was fur underneath.

There are several notable claims of lycanthropy that took place during these werewolf hunts. In 1573, an alleged werewolf, Gilles Garnier, was burned at the stake. In 1589, a man known as Stubbe Peter or Peter Stubbe, was executed near Cologne, Germany for cannibalism and multiple murders. He claimed he had a belt that allowed him to become a werewolf. In 1603, a young man named Jean Grenier­ claimed responsibility for a series of murders and disappearances, saying he had a skin that let him become a wolf. A court determined that Grenier was insane and confined him to a monastery.

In France, between 1520 and 1630, there were more than 30,000 recorded cases of people who claimed to be -- or appeared to be -- werewolves [source: Dunlop]. As with the witch trials, there were probably several simultaneous causes for this, and for the werewolf hunts:

  • Hypertrichosis: A genetic disorder linked to the X-chromosome can cause people to grow very thick hair over their faces and bodies. People with this condition can physically resemble werewolves, but it's extremely rare. One variety, congenital generalized hypertrichosis, is known to affect only 19 people in one Mexican family [source: Glausiusz].
  • Ergot poisoning: Ergot is a fungus that can infest grains like barley and wheat, and eating it can cause hallucinations. Ergot poisoning has also been suggested as a cause of the witch trials in Salem, Mass.
  • Rabies: Many mammals can carry and transmit rabies, typically through biting. Rabies is fatal without immediate treatment. In its advanced stages, it can cause agitation and hallucinations. A rabies epidemic may have caused wolves and dogs to bite humans, who then could have exhibited werewolf-like tendencies.
  • Wolf hybrids: Healthy wolves don't generally attack people without provocation, but aggressive hybrids of wolves and dogs may have attacked villages, leading to the idea of violent werewolves.
  • Porphyria: The supernatural condition most often associated with porphyria is vampirism. Porphyria causes sensitivity to light. In some cases, exposure to sunlight causes lesions and blisters, which can sprout fine hair during healing. Advanced porphyria can also lead to hallucinations.
  • Collective hysteria: As unlikely as it sounds, the sudden, simultaneous onset of psychological symptoms in a large group of people is a recorded phenomenon.

Wolves aren't a large part of the industrial world -- perhaps that's why many of today's werewolf stories take place in cities.

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The belief that werewolves are real isn't confined to the distant past, though. In the 1930s, researchers working in the part of Africa now known as Ghana reported a widespread belief that people could turn into hyenas. These shape-shifters were typically witches living in the grasslands. As recently as the 1980s, an obscure practice in the Iberian Peninsula -- the part of Europe that includes Spain and Portugal -- was intended in part to prevent children from becoming werewolves. This practice involved older children acting as godparents for their younger siblings, beginning with the seventh or ninth child [source: da Silva]. According to folk tales in this part of the world, werewolves recruit new members from excess children. Children who are born in the caul, or with part of their amniotic sac covering their face -- may be more susceptible to becoming werewolves, or, conversely, healers.

In industrialized parts of the world, the idea of werewolves, or of wolves in general, can seem distant and archaic. Perhaps that's why many more recent depictions present lycanthropy as a manageable condition. Werewolves are ordinary people with a keen sense of smell who happen to be unpleasant to be around for a few days each month.

You can learn more about werewolves and the supernatural by following the links on the next page.