According to the neighbors, one woman would get on her motorcycle and go riding late at night, although she had no idea because she was sleepwalking. Others cook meals, preach sermons, and commit murder while sleeping. It's estimated that 30 percent of us sleepwalk at one time or another, but we really don't know because we sleep through it.
Although it’s thought to be triggered by stress, anxiety, and alcohol, it is totally unknown why we do it. Are we simply on auto-pilot? Trying to fulfill our fantasies? Or perhaps something stranger…
Science hasn’t always provided satisfactory answers to the many questions raised around sleepwalking. Throughout history, the mysteries of somnambulance have lead many to come up with their own theories—drawing on spirituality, pseudo-science, and folklore—with sleepwalkers seeming to exist somewhere between this world and another.
Read a short history of sleepwalking that covers famous cases, scientific research, and pop culture, at Vice.