Experimental Hypnosis

1886

Joseph Delboeuf (1831–1896), Clark Hull (1884–1952), Ernest Hilgard (1904–2001), Josephine Hilgard (1906–1989)

Hypnotism as a subject of modern scientific study dates from the late nineteenth century and the investigations of Joseph Delboeuf, a psychologist and philosopher working in France. Skeptical of the claims being made by other practitioners, such as Jean-Martin Charcot, Delboeuf conducted studies, first published in 1886, that led him to develop a typology of hypnotic subjects. But it was the work of American psychologist Clark Hull, culminating in his 1933 book Hypnosis and Suggestibility, that laid the foundation for twentieth-century psychological research.

Hull, better known for his role in developing Neobehaviorism, claimed his research established that hypnosis is a phenomenon of normal consciousness that varies by individual. In doing so, Hull sought to counter assertions that the hypnotic state may make it possible for a person to perform extraordinary feats normally outside his or her powers. His research did confirm, however, that a hypnotized person may not experience pain (a phenomenon known as hypnotic anesthesia) and may not remember the hypnotic episode after it ends (post-hypnotic amnesia). Nearly a hundred years earlier, James Braid in England and James Esdaile in India had reported the effective use of hypnosis to achieve anesthesia during surgery.

The experimental study of hypnosis has thrived since 1933, especially among psychologists. Although researchers differ on particulars, many agree that the susceptibility of subjects is critical for the success of hypnotism. Prominent investigators Ernest and Josephine Hilgard, along with their colleagues, developed the first reliable tests of hypnotic susceptibility; Josephine Hilgard also developed effective hypnotic techniques to reduce pain in children during medical treatment. The Hilgards’ research established that there are no significant gender differences in susceptibility, but that children between the ages of eight and twelve are more receptive than younger or older children.

In addition to showing a strong link between hypnotic sensibility and the ability to immerse oneself in a novel, play, or other artistic experience, researchers have also established that the hypnotized state is not a form of dreaming or sleeping, though there are some similarities.

SEE ALSO Mesmerism (1766), Multiple Personality Disorder (1885), Hysteria (1886)

In this c. 1900 poster, a hypnotist directs a group of people to do silly activities.