Suggestion

Suggestion is the psychological process by which one person guides the thoughts, feelings, or behaviour of another. Nineteenth century writers on psychology such as William James used the words "suggest" and "suggestion" in senses close to those they have in common speech—one idea was said to suggest another when it brought that other idea to mind. Early scientific studies of hypnosis by Clark Leonard Hull and others extended the meaning of these words in a special and technical sense (Hull, 1933). The original neuro-psychological theory of hypnotic suggestion was based upon the ideo-motor reflex response of William B. Carpenter and James Braid.

Hypnosis

Modern scientific study of hypnosis, which follows the pattern of Hull's work, separates two essential factors: "trance" and suggestion. The state of mind induced by "trance" is said to come about via the process of a hypnotic induction—essentially instructing and suggesting to the subject that they will enter a hypnotic state. Once a subject enters hypnosis, the hypnotist gives suggestions that can produce sought effects. Commonly used suggestions on measures of "suggestibility" or "susceptibility" (or for those with a different theoretical orientation, "hypnotic talent") include suggestions that one's arm is getting lighter and floating up in the air, or that a fly is buzzing around one's head. The "classic" response to an accepted suggestion that one's arm is beginning to float in the air is that the subject perceives the intended effect as happening involuntarily.