Editing Extrasensory perception (section)

==Skepticism==
{{See also|Parapsychology#Scientific reception}}

[[Parapsychology]] is the study of paranormal psychic phenomena, including ESP. Parapsychology has been criticized for continuing investigation despite being unable to provide convincing evidence for the existence of any psychic phenomena after more than a century of research.<ref name="Cordón">{{Cite book |last=Cordón |first=Luis A. |title=Popular psychology: an encyclopedia |publisher=[[Greenwood Publishing Group|Greenwood Press]] |location=Westport, Connecticut |year=2005 |page=[https://archive.org/details/popularpsycholog0000cord/page/182 182] |isbn=978-0-313-32457-4 |quote=The essential problem is that a large portion of the scientific community, including most research psychologists, regards parapsychology as a pseudoscience, due largely to its failure to move beyond null results in the way science usually does. Ordinarily, when experimental evidence fails repeatedly to support a hypothesis, that hypothesis is abandoned. Within parapsychology, however, more than a century of experimentation has failed even to conclusively demonstrate the mere existence of paranormal phenomenon, yet parapsychologists continue to pursue that elusive goal. |url=https://archive.org/details/popularpsycholog0000cord/page/182 }}</ref> The [[scientific community]] rejects ESP due to the absence of an evidence base, the lack of a theory which would explain ESP and the lack of positive experimental results; it considers ESP to be [[pseudoscience]].<ref>Diaconis, Persi. (1978). ''Statistical Problems in ESP Research''. Science New Series, Vol. 201, No. 4351. pp. 131–136.</ref><ref>Bunge, Mario. (1987). "Why Parapsychology Cannot Become a Science". ''Behavioral and Brain Sciences'' 10: 576–577.</ref><ref>Hines, Terence. (2003). ''Pseudoscience and the Paranormal''. Prometheus Books. pp. 117–145. {{ISBN|1-57392-979-4}}</ref><ref>{{cite web
|url = http://www.skepdic.com/esp.html |title = ESP (extrasensory perception)|access-date = 2007-06-23|author = Robert Todd Carroll|publisher = Skeptic's Dictionary!}}</ref><ref>Goldstein, Bruce E. (2010). ''Encyclopedia of Perception''. Sage. pp. 411–413. {{ISBN|978-1-4129-4081-8}}</ref>

The [[scientific consensus]] does not view extrasensory perception as a [[scientific phenomenon]].<ref>Cogan, Robert. (1998). ''Critical Thinking: Step by Step''. University Press of America. p. 227. {{ISBN|978-0761810674}} "When an experiment can't be repeated and get the same result, this tends to show that the result was due to some error in experimental procedure, rather than some real causal process. ESP experiments simply have not turned up any repeatable paranormal phenomena."</ref><ref>Wynn, Charles M; Wiggins, Arthur W. (2001). ''Quantum Leaps in the Wrong Direction: Where Real Science Ends... and Pseudoscience Begins''. Joseph Henry Press. p. 165. {{ISBN|978-0309073097}} "Extrasensory perception and psychokinesis fail to fulfill the requirements of the scientific method. They therefore must remain pseudoscientific concepts until methodological flaws in their study are eliminated, and repeatable data supporting their existence are obtained."</ref><ref>Zechmeister, Eugene B; Johnson, James E. (1992). ''Critical Thinking: A Functional Approach''. Brooks/Cole Pub. Co. p. 115. {{ISBN|0534165966}} "There exists no good scientific evidence for the existence of paranormal phenomena such as ESP. To be acceptable to the scientific community, evidence must be both valid and reliable."</ref><ref>[[Milton A. Rothman|Rothman, Milton A.]] (1988). ''A Physicist's Guide to Skepticism''. Prometheus Books. p. 193. {{ISBN|978-0-87975-440-2}} "Transmission of information through space requires transfer of energy from one place to another. Telepathy requires transmission of an energy-carrying signal directly from one mind to another. All descriptions of ESP imply violations of conservation of energy in one way or another, as well as violations of all the principles of information theory and even of the principle of causality. Strict application of physical principles requires us to say that ESP is impossible."</ref><ref>Myers, David. (2004). ''Intuition: Its Powers and Perils''. Yale University Press. p. 233. {{ISBN|0-300-09531-7}} "After thousands of experiments, no reproducible ESP phenomenon has ever been discovered, nor has any researcher produced any individual who can convincingly demonstrate psychic ability."</ref><ref>[[Michael Shermer|Shermer, Michael]] (2003).[https://michaelshermer.com/2003/02/psychic-drift/ "Psychic drift: Why most scientists do not believe in ESP and psi phenomena"]. ''Scientific American'' '''288''': 2. {{retrieved|access-date=February 25, 2019}}</ref><ref>Stein, Gordon. (1996). ''The Encyclopedia of the Paranormal''. Prometheus Books. p. 249. {{ISBN|1-57392-021-5}} "Mainstream science is on the whole very dubious about ESP, and the only way that most scientists will be persuaded is by a demonstration that can be generally reproduced by neutral or even skeptical scientists. This is something that parapsychology has never succeeded in producing."</ref> [[Scientific skeptics|Skeptics]] have pointed out that there is no viable theory to explain the mechanism behind ESP, and that there are historical cases in which flaws have been discovered in the experimental design of parapsychological studies.<ref>
{{cite web
| url = http://skepdic.com/esp.html
| title = ESP (extrasensory perception)
| access-date = 2006-09-13
| author = Carroll, Robert Todd
| year = 2005
| publisher = The Skeptic's Dictionary
}}</ref>

There are many criticisms pertaining to experiments involving extrasensory perception, particularly surrounding methodological flaws. These flaws are not unique to a single experimental design, and are effective in discrediting much of the positive research surrounding ESP. Many of the flaws seen in the [[Zener cards]] experiment are present in the Ganzfeld experiment as well. First is the stacking effect, an error that occurs in ESP research. Trial-by-trial feedback given in studies using a "closed" ESP target sequence (e.g., a deck of cards) violates the condition of independence used for most standard statistical tests. Multiple responses for a single target cannot be evaluated using statistical tests that assume independence of responses. This increases the likelihood of card counting and, in turn, increases the chances for the subject to guess correctly without using ESP. Another methodological flaw involves cues through sensory leakage, for example, when the subject receives a visual cue. This could be the reflection of a Zener card in the holder's glasses. In this case, the subject is able to guess the card correctly because they can see it in the reflection, not because of ESP. Finally, poor randomization of target stimuli could be happening. Poor shuffling methods can make the orders of the cards easier to predict, or the cards could have been marked and manipulated, again, making it easier to predict which cards come next.<ref>Milton, J. & Wiseman, R. (1999). "Does psi exist? Lack of replication of an anomalous process of information transfer". ''Psychological Bulletin'' 125, 387–191. Meta-analysis of parapsychological research over ten years following agreement on methodological criteria by proponents and skeptics.</ref> The results of a meta-analysis found that when these errors were corrected and accounted for, there was still no significant effect of ESP. Many of the studies only appeared to have significant occurrence of ESP, when in fact, this result was due to the many methodological errors in the research.

===Dermo-optical perception===
{{Main|Dermo-optical perception}}
In the early 20th century, [[Joaquin María Argamasilla]], known as the "Spaniard with X-ray Eyes", claimed to be able to read handwriting or numbers on [[dice]] through closed metal boxes. Argamasilla managed to fool [[Gustav Geley]] and [[Charles Richet]] into believing he had genuine [[psychic]] powers.<ref>{{cite book |first=Massimo |last=Polidoro |author-link=Massimo Polidoro |year=2001 |title=Final Séance: The Strange Friendship Between Houdini and Conan Doyle |publisher=Prometheus Books |pages=[https://archive.org/details/secretsofpsychic0000poli/page/171 171–172] |isbn=978-1591020868 |url=https://archive.org/details/secretsofpsychic0000poli/page/171 }}</ref> In 1924, he was exposed by [[Harry Houdini]] as a fraud. Argamasilla peeked through his simple blindfold and lifted the edge of the box, so he could look inside it without others noticing.<ref>[[Joe Nickell]]. (2007). ''Adventures in Paranormal Investigation''. The University Press of Kentucky. p. 215. {{ISBN|978-0813124674}}</ref>

Science writer [[Martin Gardner]] has written that the ignorance of blindfold deception methods has been widespread in investigations into objects at remote locations from persons who claim to possess second sight. Gardner documented various conjuring techniques psychics such as Rosa Kuleshova, Lina Anderson and [[Nina Kulagina]] have used to peek from their blindfolds to deceive investigators into believing they used second sight.<ref>{{cite book |first=Martin |last=Gardner |author-link=Martin Gardner |year=2003 |title=Are Universes Thicker Than Blackberries? |publisher=W. W. Norton & Company |pages=225–243 |isbn=978-0393325720}}</ref>