The Werewolf Syndrome: Compulsive Bestial Slaughterers
The belief in the possibility that humans could change shape has been traced to 600 B.C., when King Nebuchadnezzar in the Bible thought he'd suffered from a condition that involved romping around as a wild beast for four years and growing out his hair. By the 1500s in France, it was a diagnosable medical condition, known as lycanthropy. (In some countries, people also thought they could shift their shape into other creatures, such as bear, leopards, jackals, tigers, and birds.) Two of the most informative early sources about the myths were The Book of Were-Wolves, by Sabine Baring-Gould, a nineteenth-century archaeologist and historian, and The Werewolf, by Montague Summers. Both tracked the shape-shifting ideas from ancient times and across different cultures. Summers believed that these man-beasts were real and the result of some sort of encounter with Satan, which either produced lunacy via possession or the actual ability to shape-shift.
One that Baring-Gould relates from Scandinavia is a typical tale: A man and his son, both bandits, came upon two sleeping men in possession of wolf skins. They donned them and could not get them off. When they began to feel and howl like wolves, they went into the woods to slay hapless travelers together.
But these practices were taboo, and for some people taboo subjects acquired an erotic aura. These folks dressed in wolf-skins at night, according to Summers, as a way to contact Satan for the beast's special powers. When they managed to make "the change," says the lore, they were granted a period of complete abandon into blood and violence. Tales were told around Europe of hunters who hacked off the paw of a wolf only to find a woman's hand in their pouch and a woman in town with a mysteriously bandaged arm. That still plays out in novels and movies today.
Popular stories play up the idea that the transformation is effected by the cycles of the moon, with the night of the full moon having the power to physically turn a person into a marauding wolf. He or she can then lope about, killing as they please and having no memory of it. When the night's over, they return to human form, often with the taste of blood in their mouths and sometimes with dead animals in their possession. They might believe they had nightmares about killing, and the evidence that they did it is repellant for them. Those who grasp that they've been cursed may attempt to lock themselves into barred rooms to prevent any more killing. They warn their loved ones not to let them out, beg for release though they might. In the twentieth century renditions, anyway, the werewolves are often full of remorse and feel captive to a state not of their choosing. They are destroyed only by a silver bullet to the heart.
But that's fiction. In the real world, lycanthropy has long been considered a form of lunacy that compels people to eat raw meat, attack others, grow their hair, and run on all fours. Baring-Gould offers another interesting account from the sixteenth century.