Hypnotism is a suggested state of trance, or a deeply focused state of mind. The brain experiences hypnotic states on its own, and can also be led into such states by many sources of external stimuli, including a book, music, television or a person skilled in the art of suggestion. Some factors make some people more susceptible to hypnosis than others.
During hypnosis, an EEG will read alpha brain waves similar to those seen during meditation. Hypnosis is accepted in many scientific research communities. Skeptics argue that proving hypnotism's effect is impossible because it is inseparable from a placebo effect.
Though the neural reason for hypnosis is unclear, trance is an altered state of consciousness in which the subject is neither fully asleep nor fully awake. In the 1950s, Stanford University devised the Stanford Scale, a system for measuring hypnotizability that is still in use today.
Everyone goes into several hypnotic states at some point in their day, but not everyone is able to be hypnotized by suggestion. According to Penn State, studies have been unsuccessful in linking genetics or personality traits to hypnotism. Patients with an IQ below 70, though, were found to be more difficult to hypnotize.
According to a 1995 study by the psychology department of the University of Westchester, Pennsylvania, findings show that marijuana use increases hypnotizability and the depth of the hypnotic trance in people who already respond well to hypnotism.
According to Penn State, in 1784, Benjamin Franklin debunked hypnotism, which was then called "mesmerism," calling it "utterly fallacious." Today, in addition to its uses in entertainment, hypnosis is widely used in brain analysis and amnesia research.
According to hypnotist Tom Nicoli, the most important deciding factor in a person's response to hypnotism is her willingness to be hypnotized.