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Precognition (from the Latin præ-, "before" and cognitio, "acquiring knowledge"), also called future sight, and second sight, is an alleged psychic ability to see events in the future.
As with other forms of extrasensory perception, there is no evidence that precognition is a real ability possessed by anyone. However it still appears within movies, books, and discussion within the parapsychology community, with claimed precognition of earthquakes sometimes covered by the newsmedia.
Scientific investigation of extrasensory perception is complicated by the definition which implies that the phenomena go against established principles of science. Specifically, precognition would violate the principle that an effect cannot occur before its cause. There are established biases affecting human memory and judgment of probability that sometimes create convincing but false impressions of precognition.
Belief in precognition has been related to superstition. A 1978 Gallup poll found that 37% of Americans surveyed believed in precognition. According to psychologists Tobacyk and Milford, belief in precognition was greater in college women than in men, and a 2007 Gallup poll found that women were more prone to superstitious beliefs in general.
A 2013 study discovered that greater belief in precognition was held by those who feel low in control, and the belief can act as a psychological coping mechanism.
In the early 20th century J. W. Dunne, a British aeronautics engineer, recorded each of his dreams as they occurred to him, identifying any correspondences between his future experiences and his recorded dreams. In 1927, he reported his findings, in An Experiment with Time. In this work, he alleges that 10% of his dreams appeared to represent some future event, either in his own life or an event that occurred elsewhere. Dunne concluded that precognitive dreams are common: he claims that many people unknowingly have them. Dunne also wrote about an experiment he conducted recording the dreams of other participants, and sought to associate them with subsequent experiences. Dunne felt these confirmed his claims, but a 1933 independent experiment failed to replicate his findings.
The first ongoing and organized research program on precognition was instituted by Joseph Banks Rhine in the 1930s at Duke University's Parapsychology Laboratory. Rhine used a method of forced-choice matching in which participants guessed the order of a deck of 25 cards, each five of which bore one of five geometrical symbols. The experiment was not blinded, so participants were able to read the symbols through the back of the cards, and were able to see and hear the experimenters throughout the experiment. This sensory leakage contributed to Rhine's experiments being discredited.
Experiments by Samuel G. Soal ran forced-choice ESP experiments in which someone attempted to identify which of five animal pictures a subject in another room was looking at. Their performance on this task was at chance, but when the scores were matched with the card that came after the target card, three of the thirteen subjects showed a very high hit rate. Rhine described Soal's work as "a milestone in the field". George Price reviewed the experiment in Science in 1955, and concluded that the positive results not attributable to error were more likely the result of deliberate fraud. This prompted several replies that Price's criticism was unfair. In 1978, the experiments were exposed as fraudulent. The statistician and paragnost Betty Markwick, while seeking to vindicate Soal, discovered that he had altered his data to create all the extra hits and give the study its statistical significance. The untainted experimental results showed no evidence of precognition in the hits or the ratios.
Following these experiments, a more automated technique of experimentation was introduced that did not rely on hand-scoring of equivalence between targets and guesses, and in which the targets could be more reliably and readily tested at random. This involved testing for precognition with the use of high-speed random event generators (REG), as introduced by Helmut Schmidt in 1969, and at the Princeton Engineering Anomalies Research Lab. The psychologist C. E. M. Hansel found flaws in all of Schmidt's experiments into precognition. Hansel found that necessary precautions were not taken, there was no presence of an observer or second-experimenter in any of the experiments, no counterchecking of the records and no separate machines used for high and low score attempts.
In 2011, the psychologist Daryl Bem, a Professor Emeritus at Cornell University, published the article "Feeling the Future: Experimental Evidence for Anomalous Retroactive Influences on Cognition and Affect" in the Journal of Personality and Social Psychology, offering statistical evidence for precognition. The article's findings challenged modern scientific conceptions about the unidirectional nature of time. Its presentation by a respected researcher and its publication by an upper tier journal engendered much controversy. In addition to criticism of the paper itself, the paper's publication prompted a wider debate on the validity of peer review process for allowing such a paper to be published. Bem appeared on MSNBC and The Colbert Report to discuss the experiment.
Jeffrey Rouder and Richard Morey who applied a meta-analytical Bayes factor to Bem's data concluded "We remain unconvinced of the viability of ESP. There is no plausible mechanism for it, and it seems contradicted by well-substantiated theories in both physics and biology. Against this background, a change in odds of 40 is negligible.
After evaluating Bem's nine experiments, psychologist James Alcock said that he found metaphorical "dirty test tubes," or serious methodological flaws, such as changing the procedures partway through the experiments and combining results of tests with different chances of significance. It is unknown how many tests were actually performed, nor is there an explanation of how it was determined that participants had "settled down" after seeing erotic images. Alcock concludes that almost everything that could go wrong with Bem's experiments did go wrong. Bem's response to Alcock's critique appeared online at the Skeptical Inquirer website and Alcock replied to these comments in a third article at the same website.
In 2012, the same journal that published Bem's original experiments, the Journal of Personality and Social Psychology (Vol. 103, No. 6), published “Correcting the Past: Failures to Replicate Psi” by Jeff Galek of Carnegie Mellon University, Robyn A. LeBoeuf of the University of Florida, Leif D. Nelson of the University of California at Berkeley, and Joseph P. Simmons of the University of Pennsylvania. The paper reported seven experiments testing for precognition that "found no evidence supporting its existence.”
There is no known mechanism for precognition. Precognition would violate the principle of antecedence (causality), that an effect does not happen before its cause.
The physicist John Taylor has written "since only positive energies are possible, particles going backward in time cannot exist. Any claim that they do is purely a fantasy in the mind of the parapsychologist. There is therefore no direct justification for precognition from physics... experimental evidence from high energy physics is strongly against it."
Neuroscientist Samuel Schwarzkopf has written that precognition contradicts "most of the neuroscience and psychology literature, from electrophysiology and neuroimaging to temporal effects found in psychophysical research."
Various psychological processes have been offered to explain experiences of apparent precognition. These include:
Some psychologists have explained the apparent prevalence of precognitive dreams in terms of memory biases, namely a selective memory for accurate predictions and distorted memory so that dreams are retrospectively fitted onto subsequent events. In one experiment, subjects were asked to write down their dreams in a diary. This prevented the selective memory effect, and the dreams no longer seemed accurate about the future. Another experiment gave subjects a fake diary of a student with apparently precognitive dreams. This diary described events from the person's life, as well as some predictive dreams and some non-predictive dreams. When subjects were asked to recall the dreams they had read, they remembered more of the successful predictions than unsuccessful ones.
An early inquiry into allegedly prophetic dreams was done by Aristotle in his On Divination in Sleep. His criticism of these claims appeals to the fact that "the sender of such dreams should be God", and "the fact that those to whom he sends them are not the best and wisest, but merely commonplace persons." Thus: "Most [so-called prophetic] dreams are, however, to be classed as mere coincidences...", here "coincidence" being defined by Aristotle as that which does not take "place according to a universal or general rule" and referring to things which are not of themselves by necessity causally connected. His example being taking a walk during an eclipse, neither the walk nor the eclipse being apparently causally connected and so only by "coincidence" do they occur simultaneously.
In 1932 Charles Lindbergh's infant son was kidnapped and murdered. The psychologists Henry Murray and D. R. Wheeler tested precognitive dreams by inviting the public to report any dreams of the child. A total of 1,300 dreams were reported. Only five percent envisioned the child dead and only 4 of the 1,300 envisioned the location of the body as buried amongst trees. This number was no better than chance.
David Ryback, a psychologist in Atlanta, used a questionnaire survey approach to investigate precognitive dreaming in college students. His survey of over 433 participants showed that 290 or 66.9 percent reported some form of paranormal dream. He rejected many of these reports, but claimed that 8.8 percent of the population was having actual precognitive dreams.
Dreams which appear to be precognitive may in fact be the result of the Law of large numbers. The psychologist Stuart Sutherland has written:
Suppose that you can remember ten incidents from a night's dreaming, at least when prompted by a similar incident occurring a day. Now consider how many incidents occur during a day, including those you read about in the paper, watch on television or hear from your friends. There are a vast number and it is highly probable that from time to time one of them will, at least to some extent, resemble one of those from your dreams. When one or more of these coincidences occur, people are likely to conclude that dreams foretell the future.
Robert Todd Carroll, author of The Skeptic's Dictionary put it this way: "Say the odds are a million to one that when a person has a dream of an airplane crash, there is an airplane crash the next day. With 6 billion people having an average of 250 dream themes each per night, there should be about 1.5 million people a day who have dreams that seem clairvoyant."