Psychologists have a lot to say about things in this movie Split. According to what some psychologists say, much like a brain tumour can cause psychic episodes, there are some people with multiple personalities who have telekinesis-like Dr. Fletcher’s diagnose in this movie. Also, some psychologists believe just thinking about something is enough to cause it to happen, so be careful what you think. The whole idea of multiple personalities goes back a long ways to biblical times when a man was possessed by many different demons called Legion.