Anomalistic psychology
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.
[2] 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.
[9] Other early scientists who studied anomalistic psychology include Millais Culpin, Joseph Jastrow, Charles Arthur Mercier and Ivor Lloyd Tuckett.
[12] The psychologist David Marks wrote that paranormal phenomena can be explained by magical thinking, mental imagery, subjective validation, coincidence, hidden causes, and fraud.
[13] 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.
[19] A study (Lange and Houran, 1998) suggested that poltergeist experiences are delusions "resulting from the affective and cognitive dynamics of percipients' interpretation of ambiguous stimuli".
Some of these factors included "the variance of local magnetic fields, size of location and lighting level stimuli of which witnesses may not be consciously aware".
[23] Mediums are known for employing a technique called cold reading which involves obtaining information from the sitter's behavior, clothing, posture, and jewellery.
[24][25] In a series of fake seance experiments (Wiseman et al. 2003), an actor suggested to paranormal believers and disbelievers that a table was levitating when, in fact, it remained stationary.
In another experiment the believers had also reported that a handbell had moved when it had remained stationary and expressed their belief that the fake seances contained genuine paranormal phenomena.
The results concluded that the fall in blood pressure in all three of the groups was caused by the psychosocial approach and the placebo effect of the trial itself.
On this subject (Harris, 1985) wrote: If you are doing a really convincing job, then you should be able to put a bent key on the table and comment, 'Look, it is still bending', and have your spectators really believe that it is.
[32]In an experimental study (Wiseman and Greening, 2005) two groups of participants were shown a videotape in which a fake psychic placed a bent key on a table.
[33] Research has suggested that in cases the participants of remote viewing experiments are influenced by subjective validation, a process through which correspondences are perceived between stimuli that are in fact associated purely randomly.
In an experiment (Schienle et al. 1996) 22 believers and 20 skeptics were asked to judge the covariation between transmitted symbols and the corresponding feedback given by a receiver.
[35] The results from another telepathy experiment involving 48 undergraduate college students (Rudski, 2002) were explained by hindsight and confirmation biases.
