psychokinesis, in parapsychology, the action of mind on matter, in which objects are supposedly caused to move or change as a result of mental concentration upon them. The physical nature of psychokinetic effects contrasts with the cognitive quality of extrasensory perception (ESP), the other major grouping of parapsychological phenomena. Claimed effects of psychokinesis include levitation and metal bending; such displays are common, though fraudulent, in theatrical magic.
Despite experimental investigation, scientific evidence supporting the existence of psychokinesis is lacking. In an example of a psychokinetic test, the subject attempts by thinking or willing to influence thrown dice, causing a certain die face to turn up or causing the die to land in a certain area. Other experiments have focused on the ability of subjects to influence outcomes of random number generators. Some researchers have interpreted the results of such experiments as revealing the existence of very small effects in which consciousness influences outcomes in such random physical systems. Other studies, however, indicate that such conclusions are the result of various forms of bias, including publication bias and confirmation bias. Hence, experimental results, as with other parapsychological phenomena, have been inconclusive.