Almost every culture on Earth has a variation of the werewolf legend – an ordinary human with the power to change form into a wild animal, or some bizarre hybrid of the two. In Europe it’s wolves, in Africa wild cats like cheetahs, et cetera. Author Caroline Taylor Stewart has a clear and simple hypothesis as to why this monster is so widespread, and it has to do with survival. Human civilization grew, in part, thanks to our ability to use tools. Crafting weapons was one way we made hunting easier, but we also learned the art of disguise. Early hunters would kill a wolf and then wear its skin so as to approach other wolves without raising alarm. Those men disguised as beasts were often credited with animalistic natures, so it’s a short path from primitive hunters to actual shapeshifters.