Historical Development

Among the early achievements of the British group was the investigation of hypnotism, a field later claimed by medicine and psychology. The society also investigated phenomena produced at spiritualistic seances and the claims of spiritualism. Psi phenomena to be investigated were classified as either physical or mental. The physical effects, or PK, include the movement of physical objects or an influence upon material processes by the apparent direct action of mind over matter. The mental manifestations, or ESP, include telepathy, which is the direct transmission of messages, emotions, or other subjective states from one person to another without the use of any sensory channel of communication; clairvoyance, meaning direct responses to a physical object or event without any sensory contact; and precognition, or a noninferential response to a future event.

One of the first specific investigations in the field was the examination, by the British chemist and physicist Sir William Crookes, of the phenomena produced at seances held by the Scottish medium Daniel Dunglas Home. Home, a physical medium, held his seances in full light, and the validity of the paranormal phenomena he produced has never been successfully impugned. The contents of verbal utterances by mental mediums were also studied. Significant early research involved the American medium Leonore E. Piper, whose apparent psychical gifts were discovered by the American philosopher and psychologist William James. Other lines of investigation dealt with psychic experiences that seemed to occur spontaneously in everyday life, and involved the controlled testing of persons with apparently outstanding ESP abilities.

Rhine’s Laboratory

In the U.S., one of the earliest groups to become active in parapsychology was the Parapsychology Laboratory of North Carolina’s Duke University, which began publishing literature in the 1930s. There, under the direction of the American psychologist Joseph Banks Rhine, methods were developed that advanced psychical investigations from the correlations of isolated and often vague anecdotal reports to a mathematical study based on statistics and the laws of probability.

In the experiments dealing with ESP, Rhine and his associates used mainly a deck of 25 cards, somewhat similar to ordinary playing cards but bearing on their faces only five designs: star, circle, cross, square, and wavy lines. If a subject correctly named 5 out of the shuffled deck of 25 concealed cards, that was considered pure chance. Certain subjects, however, consistently named 6 out of 10 cards correctly; so Rhine and his associates concluded that this demonstrated the existence of ESP. In their experiments on PK, the group used ordinary dice that were thrown from a cup against a wall or tumbled in mechanically driven cages. In these tests, an apparent relationship was found between the mental effort of subjects to “will” particular faces of the dice to appear upward and the percentage of times the faces actually did so. The results obtained in many individual experiments and in the research as a whole, Rhine and his workers decided, could not reasonably be attributed to the fluctuations of chance.

Rhine retired from Duke University in 1965 and transferred his research to a privately endowed organization, the Foundation for Research on the Nature of Man. Since that time parapsychology has become better established in other universities, as illustrated by the offering of credit courses in the subject in increasing numbers. In addition, independent research centers continue to be founded, among them the American Society for Psychical Research, with headquarters in New York City. The Parapsychological Association, an international group of scholars actively working in the field, was formed in 1957 and was granted affiliation status by the American Association for the Advancement of Science in 1969.

Criticisms

Although parapsychologists are increasingly employing and refining scientific methodologies for their observations, one of the chief criticisms of their work is that experiments in psi phenomena can rarely be duplicated. Under the most rigorous laboratory controls, for example, experiments on phenomena such as out-of-body experiences—in which individuals demonstrate an apparent ability to locate their center of perception outside their bodies—indicate that even reputable psychics are rarely able to duplicate earlier, high-scoring performances. The scores of such individuals, in fact, tend to drop to the level of probability the more the experiment is repeated. Nonparapsychologists find psi experiments even more difficult to repeat, and a majority of conventional scientists dismiss parapsychology findings as unscientific or at best inconclusive.

A similar criticism is based on the claim by most parapsychologists that psi phenomena occur beyond the law of causality, which is one of the fundamental premises of any scientific investigation. Indeed, results of psi experiments often turn out to be far from or even contradictory to the original predictions. Parapsychologists admit that psi phenomena fall so far outside ordinary comprehension that they are often unsure whether an ESP event or a PK event has occurred; Rhine himself stated that one kind of event could not