In psychology, anomalistic psychology is the study of human behaviour and experience connected with what is often called the paranormal, with few assumptions made about the validity (or otherwise) of the reported phenomena.
Early history
According to anomalistic psychology, paranormal phenomena have naturalistic explanations resulting from psychological and physical factors which have given the false impression of paranormal activity to some people. There were many early publications that gave rational explanations for alleged paranormal experiences.
The physician John Ferriar wrote An Essay Towards a Theory of Apparitions in 1813 in which he argued that sightings of ghosts were the result of optical illusions. Later, the French physician Alexandre Jacques François Brière de Boismont published On Hallucinations: Or, the Rational History of Apparitions, Dreams, Ecstasy, Magnetism, and Somnambulism in 1845 in which he claimed sightings of ghosts were the result of hallucinations. William Benjamin Carpenter, in his book Mesmerism, Spiritualism, Etc: Historically and Scientifically Considered (1877), wrote that Spiritualist practices could be explained by fraud, delusion, hypnotism and suggestion. The British psychiatrist Henry Maudsley, in Natural Causes and Supernatural Seemings (1886), wrote that so-called supernatural experiences could be explained in terms of disorders of the mind and were simply "malobservations and misinterpretations of nature".
In the 1890s, the German psychologist Max Dessoir and psychiatrist Albert Moll formed the "critical occultism" position. This viewpoint interpreted psychical phenomena naturalistically. All apparent cases were attributed to fraud, suggestion, unconscious cues or psychological factors. Moll wrote that practices such as Christian Science, Spiritualism and occultism were the result of fraud and hypnotic suggestion. Moll argued that suggestion explained the cures of Christian Science, as well as the apparently supernatural rapport between magnetisers and their somnambulists. He wrote that fraud and hypnotism could explain mediumistic phenomena.
Lionel Weatherly (a psychiatrist) and John Nevil Maskelyne (a magician) wrote The Supernatural? (1891) which offered rational explanations for apparitions, paranormal and religious experiences and Spiritualism. Karl Jaspers, in his book General Psychopathology (1913), stated that all paranormal phenomena are manifestations of psychiatric symptoms.
The German Zeitschrift für Kritischen Okkultismus (Journal for Critical Occultism) operated from 1926 to 1928. Psychologist Richard Baerwald was the editor, and the journal published articles by Dessoir, Moll and others. It contained "some of the most important skeptical investigations of claims of the paranormal".
Other early scientists who studied anomalistic psychology include Millais Culpin, Joseph Jastrow, Charles Arthur Mercier and Ivor Lloyd Tuckett.
Modern research
The phrase "Anomalistic Psychology" was a term first suggested by the psychologists Leonard Zusne and Warren Jones in their book Anomalistic Psychology: A Study of Magical Thinking (1989) which systematically addresses phenomena of human consciousness and behaviors that may appear to violate the laws of nature when they actually do not.
The Canadian psychologist Graham Reed published a major work on the subject The Psychology of Anomalous Experience (1972).
Various psychological publications have explained in detail how reported paranormal phenomena such as mediumship, precognition, out-of-body experiences and psychics can be explained by psychological factors without recourse to the supernatural. Researchers involved with anomalistic psychology try to provide plausible non-paranormal accounts, supported by empirical evidence, of how psychological and physical factors might combine to give the impression of paranormal activity when there had been none. Apart from deception or self-deception such explanations might involve cognitive biases, anomalous psychological states, dissociative states, hallucinations, personality factors, developmental issues and the nature of memory.
The psychologist David Marks wrote that paranormal phenomena can be explained by magical thinking, mental imagery, subjective validation, coincidence, hidden causes, and fraud. Robert Baker wrote that many paranormal phenomena can be explained via psychological effects such as hallucinations, sleep paralysis and hidden memories, a phenomenon in which experiences that originally make little conscious impression are filed away in the brain to be suddenly remembered later in an altered form.