A psychic is a person who claims to have an ability to perceive information hidden from the normal senses through extrasensory perception (ESP), or who is said by others to have such abilities. The word "psychic" is also used to describe theatrical performers, such as stage magicians, who use techniques such as prestidigitation, cold reading, and hot reading to produce the appearance of such abilities. It can also denote an ability of the mind to influence the world physically using psychokinetic powers such as those professed by Uri Geller.
Psychics appear regularly in fantasy fiction, such as in the novel The Dead Zone by Stephen King. A large industry exists whereby psychics provide advice and counsel to clients. Some famous contemporary psychics include Miss Cleo, John Edward, Danielle Egnew, and Sylvia Browne. Psychic powers are asserted by psychic detectives and in practices such as psychic archaeology and even psychic surgery.
Critics attribute psychic powers to intentional trickery or to self-delusion. In 1988 the U.S. National Academy of Sciences gave a report on the subject and concluded there is "no scientific justification from research conducted over a period of 130 years for the existence of parapsychological phenomena." A study attempted to repeat recently reported parapsychological experiments that appeared to support the existence of precognition. All attempts to repeat the results "failed to produce significant effects", and thus "do not support the existence of psychic ability."