Esper (fiction)

Extrasensory perception, ESP or Esper, also called sixth sense, includes reception of information not gained through the recognized physical senses but sensed with the mind. The term was adopted by Duke University psychologist J. B. Rhine to denote psychic abilities such as intuition, telepathy, psychometry, clairaudience, and clairvoyance, and their trans-temporal operation as precognition or retrocognition.

Parapsychology is the study of paranormal psychic phenomena, including ESP. Parapsychology has been criticized for continuing investigation despite being unable to provide convincing evidence for the existence of any psychic phenomena after more than a century of research. The scientific community rejects ESP due to the absence of an evidence base, the lack of a theory which would explain ESP, the lack of experimental techniques which can provide reliably positive results, and considers ESP to be pseudoscience.

In the 1930s, at Duke University in North Carolina, J. B. Rhine and his wife Louisa E. Rhine conducted investigation into extrasensory perception. While Louisa Rhine concentrated on collecting accounts of spontaneous cases, J. B. Rhine worked largely in the laboratory, carefully defining terms such as ESP and psi and designing experiments to test them. A simple set of cards was developed, originally called Zener cards – now called ESP cards. They bear the symbols circle, square, wavy lines, cross, and star; there are five cards of each in a pack of 25.

In a telepathy experiment, the "sender" looks at a series of cards while the "receiver" guesses the symbols. To try to observe clairvoyance, the pack of cards is hidden from everyone while the receiver guesses. To try to observe precognition, the order of the cards is determined after the guesses are made. Later he used dice to test for psychokinesis.

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