Extrasensory perception

Lore & Background

In the 1930s, at Duke University in North Carolina, J. B. Rhine and his wife Louisa E. Rhine conducted an investigation into extrasensory perception. Louisa Rhine collected accounts of spontaneous cases, while J. B. Rhine worked in the laboratory, defining terms such as ESP and psi and designing experiments. He developed a simple set of black and white cards, originally called Zener cards (now ESP cards), bearing the symbols circle, square, wavy lines, cross, and star, with five of each in a pack of 25. In telepathy experiments, a 'sender' looked at cards while a 'receiver' guessed the symbols; for clairvoyance, the pack was hidden; for precognition, the order was determined after guesses were made. Rhine later used dice to test for psychokinesis. The parapsychology experiments at Duke evoked criticism from academics. W. S. Four other psychological departments failed to replicate Rhine's results. In the 1960s, parapsychologists became interested in cognitive components of ESP, leading to procedures beyond Rhine's forced-choice methodology, including dream telepathy experiments and the ganzfeld experiments (a mild sensory deprivation procedure). Second sight, an alleged form of ESP involving visions of future or remote events, is known only from anecdotes. The scientific community rejects ESP due to absence of an evidence base, lack of a viable theory, and lack of positive experimental results, considering it pseudoscience.

Reader's Guide

Extrasensory perception holds significance primarily as a historically prominent paranormal claim that has been extensively investigated but remains unsupported by reliable evidence. The term was formalized by J. B. Rhine at Duke University in the 1930s, whose Zener card experiments became iconic in parapsychology. However, these experiments were criticized for methodological flaws including sensory leakage, poor randomization, and the stacking effect, and subsequent attempts at replication by other psychological departments failed. The scientific consensus rejects ESP as a scientific phenomenon, citing the absence of a theoretical mechanism and the prevalence of experimental errors. Skeptics have documented that many positive results were due to flawed procedures, such as subjects peeking through blindfolds or receiving visual cues. Despite over a century of research, parapsychology has been unable to provide convincing evidence for any psychic phenomena. ESP thus serves as a case study in how anecdotal reports and flawed experiments can create the illusion of a paranormal ability, while rigorous testing consistently fails to confirm its existence. Its legacy lies in the development of experimental methods in psychology and the ongoing debate about pseudoscience and scientific standards.

Did You Know?

• The term 'extrasensory perception' was adopted by Duke University botanist J. B. Rhine.
• Zener cards bear the symbols circle, square, wavy lines, cross, and star, with five of each in a pack of 25.
• Second sight is known only from anecdotes, and there is no good evidence that it exists.