According to popular legend, people turn into werewolves by being bit by a werewolf. However, other myths claim that people turn into werewolves as a punishment from a divine being for bad behavior. German folk tales explain that turning into a werewolf is a voluntary act that occurs when a person wears a belt made from the skin of a wolf.
The idea of people turning into werewolves, or lycanthropy, stems from ancient myths and stories. The "Epic of Gilgamesh," for instance, tells that the goddess Ishtar changes one of her suitors into a wolf. In another story, the god Juipter changes Lycaon into a wolf for attempting to serve him human meat. In both cases, lycanthropy is a punishment.
In other cultures, lycanthropy is both a gift and a voluntary transformation. German, Belgium and Netherlands tales state that a man would wear a belt made from wolf skin so that he could change into a wolf. He did this so that he could fight fiercely in battle. In other stories, the transformation occurs as a man removes his clothing, and the only way to regain his human shape is to put his clothes back on.
Popular literature and movies describe lycanthropy as a condition that is caught through the bite of another werewolf. One of the films that set this precedent is "The Wolf Man," made in 1941.