Telepathy

==In parapsychology==
Within [[parapsychology]], telepathy, often along with [[precognition]] and [[clairvoyance]], is described as an aspect of [[extrasensory perception]] (ESP) or "anomalous cognition" that parapsychologists believe is transferred through a hypothetical psychic mechanism they call "[[Psi (parapsychology)|psi]]".<ref name=parasoc2>[http://parapsych.org/glossary_e_k.html#e Glossary of Parapsychological terms – ESP] {{webarchive|url=https://web.archive.org/web/20110111023207/http://parapsych.org/glossary_e_k.html |date=2011-01-11 }}, [[Parapsychological Association]]. Retrieved December 19, 2006.</ref> Parapsychologists have reported experiments they use to test for telepathic abilities. Among the most well known are the use of [[Zener card]]s and the [[Ganzfeld experiment]].

===Types===
Several forms of telepathy have been suggested:<ref name=parasocie1/>
* '''Latent telepathy''', formerly known as "deferred telepathy",<ref name=sciam1>Rennie, John (1845), "Test for Telepathy", ''[[Scientific American]]'', V3#1 (1847-09-25)</ref> describes a transfer of information with an observable time-lag between transmission and reception.<ref name=parasocie1/>
* '''Retrocognitive, precognitive, and intuitive telepathy''' describes the transfer of information about the past, future or present state of an individual's mind to another individual.<ref name=parasocie1/>
* '''Emotive telepathy''', also known as remote influence<ref>Plazo, Joseph R., (2002) "Psychic Seduction." pp. 112–114 {{ISBN|0978592239}}</ref> or emotional transfer, describes the transfer of kinesthetic sensations through altered states.
* '''Superconscious telepathy''' describes use of the supposed [[Collective unconscious|superconscious]]<ref>St. Claire, David., (1989) "Instant ESP." pp. 40–50</ref> to access the collective wisdom of the human species for knowledge.

===Zener cards===
{{Main|Zener cards}}
[[File:Zener cards (color).svg|thumb|200px|right|Zener cards]]
[[Zener cards]] are marked with five distinctive symbols. When using them, one individual is designated the "sender" and another the "receiver". The sender selects a random card and visualizes the symbol on it, while the receiver attempts to determine that symbol telepathically. Statistically, the receiver has a 20% chance of randomly guessing the correct symbol, so to demonstrate telepathy, they must repeatedly score a success rate that is significantly higher than 20%.<ref name="Skepdic2">{{cite web |url=http://www.skepdic.com/zener.html |title=Zener ESP Cards |author=Carroll, Robert |date=2006-02-17 |publisher=[[The Skeptic's Dictionary]] |access-date=2006-07-18 }}</ref> If not conducted properly, this method is vulnerable to sensory leakage and [[card counting]].<ref name="Skepdic2"/>

[[Joseph Banks Rhine|J. B. Rhine]]'s experiments with Zener cards were discredited due to the discovery that [[sensory leakage]] or cheating could account for all his results such as the subject being able to read the symbols from the back of the cards and being able to see and hear the experimenter to note subtle clues.<ref>Jonathan C. Smith. (2009). [https://books.google.com/books?id=sJgONrua8IkC&dq=rhine+pseudoscience&pg=PT226 ''Pseudoscience and Extraordinary Claims of the Paranormal: A Critical Thinker's Toolkit'']. Wiley-Blackwell. {{ISBN|978-1405181228}}. "Today, researchers discount the first decade of Rhine's work with Zener cards. Stimulus leakage or cheating could account for all his findings. Slight indentations on the backs of cards revealed the symbols embossed on card faces. Subjects could see and hear the experimenter, and note subtle but revealing facial expressions or changes in breathing."</ref> Once Rhine took precautions in response to criticisms of his methods, he was unable to find any high-scoring subjects.<ref>[[Milbourne Christopher]]. (1970). ''ESP, Seers & Psychics''. Thomas Y. Crowell Company. p. 28</ref> Due to the methodological problems, parapsychologists no longer utilize card-guessing studies.<ref>[[James Alcock]]. (2011). [http://www.csicop.org/specialarticles/show/back_from_the_future ''Back from the Future: Parapsychology and the Bem Affair'']. ''[[Skeptical Inquirer]]''. "Despite Rhine's confidence that he had established the reality of extrasensory perception, he had not done so. Methodological problems with his experiments eventually came to light, and as a result parapsychologists no longer run card-guessing studies and rarely even refer to Rhine's work."</ref>

===Dream telepathy===

Parapsychological studies into [[dream telepathy]] were carried out at the [[Maimonides Medical Center]] in [[Brooklyn|Brooklyn, New York]] led by [[Stanley Krippner]] and [[Montague Ullman]]. They concluded the results from some of their experiments supported dream telepathy.<ref name=ullmanweb>{{cite book|title=Psychoanalysis and the paranormal: lands of darkness|series=Reference, Information and Interdisciplinary Subjects Series|editor1-first=Nick|editor1-last=Totton|publisher=Karnac Books| pages= 14–46|year=2003|isbn=978-1855759855|first=Montague|last=Ullman|author-link=Montague Ullman|chapter=Dream telepathy: experimental and clinical findings}}</ref> However, the results have not been independently replicated.<ref>Parker, Adrian. (1975). ''States of Mind: ESP and Altered States of Consciousness''. Taplinger. p. 90. {{ISBN|0800873742}}</ref><ref>{{cite journal | last1 = Clemmer | first1 = E. J. | year = 1986 | title = Not so anomalous observations question ESP in dreams | journal = [[American Psychologist]] | volume = 41 | issue = 10| pages = 1173–1174 | doi=10.1037/0003-066x.41.10.1173.b}}</ref><ref>[[Ray Hyman|Hyman, Ray]]. (1986). "Maimonides dream-telepathy experiments". ''Skeptical Inquirer'' 11: 91–92.</ref><ref>Neher, Andrew. (2011). ''Paranormal and Transcendental Experience: A Psychological Examination''. Dover Publications. p. 145. {{ISBN|0486261670}}</ref> The psychologist [[James Alcock]] has written the dream telepathy experiments at Maimonides have failed to provide evidence for telepathy and "lack of replication is rampant."<ref>{{cite journal | last1 = James | first1 = Alcock | author-link = James Alcock | year = 2003 | title = Give the Null Hypothesis a Chance: Reasons to Remain Doubtful about the Existence of Psi | journal = Journal of Consciousness Studies | volume = 10 | pages = 29–50 }}</ref>

The picture target experiments that were conducted by Krippner and Ullman were criticized by [[C. E. M. Hansel]]. According to Hansel there were weaknesses in the design of the experiments in the way in which the agent became aware of their target picture. Only the agent should have known the target and no other person until the judging of targets had been completed, however, an experimenter was with the agent when the target envelope was opened. Hansel also wrote there had been poor controls in the experiment as the main experimenter could communicate with the subject.<ref>[[C. E. M. Hansel|Hansel, C. E. M.]] ''The Search for a Demonstration of ESP''. In [[Paul Kurtz|Kurtz, Paul]]. (1985). ''A Skeptic's Handbook of Parapsychology''. Prometheus Books. pp. 97–127. {{ISBN|0879753005}}</ref>

An attempt to replicate the experiments that used picture targets was carried out by Edward Belvedere and David Foulkes. The finding was that neither the subject nor the judges matched the targets with dreams above chance level.<ref>{{cite journal | last1 = Belvedere | first1 = E. | last2 = Foulkes | first2 = D. | year = 1971 | title = Telepathy and Dreams: A Failure to Replicate | journal = Perceptual and Motor Skills | volume = 33 | issue = 3| pages = 783–789 | doi=10.2466/pms.1971.33.3.783| pmid = 4331356 | s2cid = 974894 }}</ref> Results from other experiments by Belvedere and Foulkes were also negative.<ref>[[C. E. M. Hansel|Hansel, C. E. M]]. (1989). ''The Search for Psychic Power: ESP and Parapsychology Revisited''. Prometheus Books. pp. 141–152. {{ISBN|0879755164}}</ref>

===Ganzfeld experiment===
When using the [[Ganzfeld experiment]] to test for telepathy, one individual is designated as the receiver and is placed inside a controlled environment where they are [[sensory deprivation|deprived of sensory input]], and another person is designated as the sender and is placed in a separate location. The receiver is then required to receive information from the sender. The nature of the information may vary between experiments.<ref name="Conscious Universe">''The Conscious Universe: The Scientific Truth of Psychic Phenomena'' by Dean I. Radin Harper Edge, {{ISBN|0062515020}}</ref>

The Ganzfeld experiment studies that were examined by [[Ray Hyman]] and [[Charles Honorton]] had methodological problems that were well documented. Honorton reported only 36% of the studies used duplicate target sets of pictures to avoid handling cues.<ref>Julie Milton, [[Richard Wiseman]]. (2002). ''A Response to Storm and Ertel (2002)''. The Journal of Parapsychology. Volume 66: 183–186.</ref> Hyman discovered flaws in all of the 42 Ganzfeld experiments and to access each experiment, he devised a set of 12 categories of flaws. Six of these concerned statistical defects, the other six covered procedural flaws such as inadequate [[documentation]], randomization and security as well as possibilities of sensory leakage.<ref name="Hyman2007">[[Ray Hyman]]. ''Evaluating Parapsychological Claims'' in Robert J. Sternberg, Henry L. Roediger, Diane F. Halpern. (2007). ''Critical Thinking in Psychology''. Cambridge University Press. pp. 216–231. {{ISBN|978-0521608343}}</ref> Over half of the studies failed to safeguard against sensory leakage and all of the studies contained at least one of the 12 flaws. Because of the flaws, Honorton agreed with Hyman the 42 Ganzfeld studies could not support the claim for the existence of psi.<ref name="Hyman2007"/>

Possibilities of sensory leakage in the Ganzfeld experiments included the receivers hearing what was going on in the sender's room next door as the rooms were not soundproof and the sender's fingerprints to be visible on the target object for the receiver to see.<ref>[[Richard Wiseman]], Matthew Smith, Diana Kornbrot. (1996). ''Assessing possible sender-to-experimenter acoustic leakage in the PRL autoganzfeld''. Journal of Parapsychology. Volume 60: 97–128.</ref><ref>[[Robert Todd Carroll]]. (2014).                                  [http://www.skepdic.com/ganzfeld.html "Ganzfeld]" in [[The Skeptic's Dictionary]].</ref>

Hyman also reviewed the autoganzfeld experiments and discovered a pattern in the data that implied a visual cue may have taken place:

{{blockquote|The most suspicious pattern was that the hit rate for a given target increased with the frequency of occurrence of that target in the experiment. The hit rate for the targets that occurred only once was right at the chance expectation of 25%. For targets that appeared twice the hit rate crept up to 28%. For those that occurred three times it was 38%, and for those targets that occurred six or more times, the hit rate was 52%. Each time a videotape is played its quality can degrade. It is plausible then, that when a frequently used clip is the target for a given session, it may be physically distinguishable from the other three decoy clips that are presented to the subject for judging. Surprisingly, the parapsychological community has not taken this finding seriously. They still include the autoganzfeld series in their meta-analyses and treat it as convincing evidence for the reality of psi.<ref name="Hyman2007"/>}}

Hyman wrote the autoganzfeld experiments were flawed because they did not preclude the possibility of sensory leakage.<ref name="Hyman2007"/> In 2010, Lance Storm, Patrizio Tressoldi, and Lorenzo Di Risio analyzed 29 ganzfeld studies from 1997 to 2008. Of the 1,498 trials, 483 produced hits, corresponding to a hit rate of 32.2%. This hit rate is [[Statistical significance|statistically significant]] with p < .001. Participants selected for personality traits and personal characteristics thought to be psi-conducive were found to perform significantly better than unselected participants in the ganzfeld condition.<ref name=StormEtAl2010>
{{cite journal | url=http://www.psy.unipd.it/~tressold/cmssimple/uploads/includes/MetaFreeResp010.pdf | journal=Psychological Bulletin | date=July 2010 | title=Meta-Analysis of Free-Response Studies, 1992–2008: Assessing the Noise Reduction Model in Parapsychology | last1=Storm |first1=Lance |last2=Tressoldi |first2=Patrizio E. |last3=Di Risio |first3=Lorenzo | volume=136 | issue=4 | pages=471–85 | access-date=2010-08-18 | pmid=20565164 | doi=10.1037/a0019457 | url-status=dead | archive-url=https://web.archive.org/web/20110124055506/http://www.psy.unipd.it/~tressold/cmssimple/uploads/includes/MetaFreeResp010.pdf | archive-date=2011-01-24 }}</ref> Hyman (2010) published a rebuttal to Storm ''et al''. According to Hyman "reliance on meta-analysis as the sole basis for justifying the claim that an anomaly exists and that the evidence for it is consistent and replicable is fallacious. It distorts what scientists mean by confirmatory evidence." Hyman wrote the ganzfeld studies have not been independently replicated and have failed to produce evidence for telepathy.<ref>Hyman, R. (2010).                             [http://drsmorey.org/bibtex/upload/Hyman:2010.pdf ''Meta-analysis that conceals more than it reveals: Comment on Storm et al''] {{webarchive|url=https://web.archive.org/web/20131103081111/http://drsmorey.org/bibtex/upload/Hyman%3A2010.pdf |date=2013-11-03 }}. (2010). Psychological Bulletin, 136. pp. 486–490.</ref> Storm ''et al''. published a response to Hyman claiming the ganzfeld experimental design has proved to be consistent and reliable but parapsychology is a struggling discipline that has not received much attention so further research on the subject is necessary.<ref>{{cite journal | last1 = Storm | first1 = L. | last2 = Tressoldi | first2 = P. E. | last3 = Di Risio | first3 = L. | year = 2010 | title = A meta-analysis with nothing to hide: Reply to Hyman (2010) | journal = Psychological Bulletin | volume = 136 | issue = 4| pages = 491–494 | doi=10.1037/a0019840| pmid = 20565166 | s2cid = 21103309 }}</ref> Rouder ''et al''. 2013 wrote that critical evaluation of Storm ''et al''.'s meta-analysis reveals no evidence for telepathy, no plausible mechanism and omitted replication failures.<ref>{{cite journal | last1 = Rouder | first1 = J. N. | last2 = Morey | first2 = R. D. | last3 = Province | first3 = J. M. | year = 2013 | title = A Bayes factor meta-analysis of recent extrasensory perception experiments: Comment on Storm, Tressoldi, and Di Risio (2010) | journal = Psychological Bulletin | volume = 139 | issue = 1| pages = 241–247 | doi=10.1037/a0029008| pmid = 23294092 }}</ref> A 2016 paper examined questionable research practices in the ganzfeld experiments.<ref>{{citation|title=Testing for Questionable Research Practices in a Meta-Analysis: An Example from Experimental Parapsychology|last1=Bierman|first1=DJ|last2=Spottiswoode|first2=JP|last3=Bijl|first3=A|year=2016|journal=PLOS ONE|volume=11|issue=5|page=1|doi=10.1371/journal.pone.0153049|quote=We consider [questionable research practices] in the context of a meta-analysis database of Ganzfeld–telepathy experiments from the field of experimental parapsychology. The Ganzfeld database is particularly suitable for this study, because the parapsychological phenomenon it investigates is widely believed to be nonexistent.|pmid=27144889|pmc=4856278|bibcode=2016PLoSO..1153049B|doi-access=free}}</ref>

===Twin telepathy===

Twin telepathy is a belief that has been described as a [[myth]] in psychological literature. Psychologists Stephen Hupp and Jeremy Jewell have noted that all experiments on the subject have failed to provide any scientific evidence for telepathy between [[twin]]s.<ref name="Hupp 2015">Hupp, Stephen; Jewell, Jeremy. (2015). ''Great Myths of Child Development''. Wiley. pp. 10–16. {{ISBN|978-1118521229}}</ref> According to Hupp and Jewell there are various behavioral and genetic factors that contribute to the twin telepathy myth "identical twins typically spend a lot of time together and are usually exposed to very similar environments. Thus, it's not at all surprising that they act in similar ways and are adept at anticipating and forecasting each other's reactions to events."<ref name="Hupp 2015"/>

A 1993 study by [[Susan Blackmore]] investigated the claims of twin telepathy. In an experiment with six sets of twins one subject would act as the sender and the other the receiver. The sender was given selected objects, photographs or numbers and would attempt to psychically send the information to the receiver. The results from the experiment were negative, no evidence of telepathy was observed.<ref>[[Richard Wiseman|Wiseman, Richard]]. (2011). ''Paranormality: Why We See What Isn't There''. Macmillan. p. 54. {{ISBN|978-0230752986}}</ref>

The skeptical investigator [[Benjamin Radford]] has noted that "Despite decades of research trying to prove telepathy, there is no credible scientific evidence that psychic powers exist, either in the general population or among twins specifically. The idea that two people who shared their mother's womb—or even who share the same DNA—have a mysterious mental connection is an intriguing one not borne out in science."<ref>[http://www.livescience.com/45405-twin-telepathy.html "The Riddle of Twin Telepathy"]. Retrieved 2014-06-06.</ref>