Extrasensory Perception (ESP)

What is ESP?

Humans are curious creatures, and as such we ask questions that extend beyond our current knowledge. One unorthodox method of doing so is Extrasensory Perception (ESP), defined by J.B. Rhine (1997) as “perception without the function of the recognized senses.” It also serves as an over-arching category that includes the psychical abilities clairvoyance, precognition, and telepathy. According to the Parapsychological Association or PA (2013a), clairvoyance is the “acquisition of information concerning an object or contemporary physical event […] directly from an external physical source (such as a concealed photograph), and not from the mind of another person,” which is similar in ability but separate in source when compared to telepathy. Telepathy, or “thought transference” is defined by the PA as the “acquisition of information concerning the thoughts, feelings, or activity of another conscious being,” where the sender of the psychic information is another individual. Lastly, precognition refers to the ability to know information about the future without the use of deduction from the current state or other logical means of prediction.

Origins and History

The first studies of ESP emerged in late 1920s by botanist Dr. J.B. Rhine. After many years of ESP studies, Rhine left Duke University in the 1960s and created the Foundation for Research on the Nature of Man, known today as the Rhine Research Center. It is the central hub for parapsychological research in the United States (Rhine Research Center, 2013). Rhine also founded the professional society for the investigation of parapsychological phenomenon, the Parapsychological Association, in 1957. The most commonly associated publication with the society is the Journal of Parapsychology. Other journals reporting findings within the discipline include Journal of the Society for Psychical Research, the Parapsychology Review, and the European Journal of Parapsychology.
Typical methodology in ESP studies includes Zener cards and the Ganzfeld method (Parapsychology Association, 2013a). Zener cards, aptly named after their creator Karl Zener (1903-1964), consisted of 25 cards that had five designs, and each design appears five times in the deck. The designs are a circle, an addition sign, three curved lines in parallel, a square, and a star.
Zener Cards.jpg

This methodology was developed in response to using a regular deck of cards, in which there are four different suits and 13 various cards for each suit. Standard procedure indicated that the shuffled deck of cards be placed with the experimenter and the subject across from the experimenter so that their view of the cards is blocked. The experimenter draws one card at a time and the participant indicates what symbol is on the card until all of the cards have been drawn. The responses are compared to the actual card drawn, and the rate of accuracy is recorded. Alternatively, the dealer of the cards can also attempt to mentally project the symbol on the drawn card to the mind of the participant, thus studying telepathy rather than clairvoyance. A multitude of studies published from the Parapsychological Association suggest that participants using Zener cards can predict the correct symbol significantly more times than chance, which is one in five, or a twenty percent chance of guessing correctly.
Following critiques of the typical Zener card design, the Ganzfeld design was adopted to improve previous designs and methodological flaws. It is a design whereby a participant is placed in a room that is controlled for sensory experience; the eyes and ears are covered, people are removed from the room, and the participant only hears white noise (parapsychology Association, 2013a). This deprivation of patterned sensory experience is said to encourage introspection and ESP. The benefit of this method is that the participant is not in the same room as the sender of the extrasensory information. Thus, if ESP is a legitimate phenomenon, then subjects of the Ganzfeld design should perform at above chance odds while in the room deprived from access to the stimuli and, for the most part, from experimenters.
Rhine alludes to the cause of ESP possibly being within the realm of the sciences, but suggests that scientific techniques and methodologies do not capture the true essence of the phenomenon. The actual cause of ESP has little description aside from being a “sixth sense” outside of the standard human senses.

But is ESP Based on Science?

On the surface, ESP appears comparable to other scientific disciplines in multiple ways; publications appear in a journal specific to the discipline, studies of phenomena are conducted, there are formal associations and societies relating to the field, and most importantly the discipline appears to progress by developing past paradigms that, in turn, encourage new research. All of these activities are reasonable expectations from modern science, however the parapsychological community misrepresents itself in these domains. Despite the appearance of typical scientific qualities, ESP is largely a stagnant, anecdotal, and irrelevant area of study. The areas of ESP to be examined are terminology, phenomena and ideology, experimental paradigms, standards for conducting studies, statistical analysis, and the publication process. Through careful examination of each, and later comparison of each to scientific standards, one is quickly determined to cast ESP out of the realm of science.


Definitions are the foundation scientific theories are built upon, and as such science requires definitions to meet standards. As we shall see, the definitions used in ESP do not meet scientific standards. Firstly, the definition of ESP blatantly rejects empiricism, shown by the use of the word “extrasensory”. This is problematic, as it suggests that the source of the effect is an unknown sense that has not been shown to exist; this demonstrates lack of verification. Lack of stringent definition offers little insight to the mechanism of such a sense, the evolutionary explanation for how such as sense could evolve, and restricts scientific exploration to weaker scientific designs, such as Zener cards. Despite parapsychological attempts to support the notion that ESP exists, evidence for it has not been reliable nor been collected in rigorous scientific settings. Other definitions related to ESP describe a wide variety of parapsychological phenomena that are also devoid from empirical form, such as clairvoyance, which invokes the use of seeing into the future. While these terms may capture the essence of what parapsychologists are interested in, they do not create a stable foundation to build theories upon. Take the parapsychological term “psi-hitting”, as defined by the PA (2013a); psi-hitting refers to the sender being able to send the message accurately to the target who then perceives it, creating a psi-hit, and overall the targets are perceived at higher than chance ratios. Thus “psi-hitters” are subjects who tend to send/receive these messages accurately at better than chances ratios. The mere presence of this term suggests that the execution of these studies could be biased; it is an indication that ESP researchers label subjects as psi-hitters and perhaps use them more often because of their apparent psychic ability. It also suggests that senders of ESP signals could have the sixth sense but simply miss the target, an un-falsifiable scapegoat that lends no progress to the theory. Perhaps the most damning aspect of these definitions is that they are unfalsifiable, or cannot be disproved. Further discussion on how this demarcates ESP as a pseudo-scientific theory follows in a later section.

Phenomena and Ideology

The phenomenon of ESP is not only based on pseudoscientific definitions, but the motivation for studies was anecdotal evidence of these experiences. The entire ideology of ESP is based on loosely controlled observations of some above-chance performances, and attributing those performances to a creative scapegoat rather than the statistically likely explanation that performance will be better than chance at least some of the time simply due to the laws of probability (Kellogg, 1936). Pseudoscientists, however, continue to use the infrequent chance significant findings as evidence that an effect truly exists despite the lack of a sound theory to predict when such significant findings should occur (Bem & Honorton, 1994). The fact that the theory of ESP, if one can call it a theory, lacks predictive power suggests further that it is irrelevant to science.

Experimental Paradigms

Issues with the experimental design of ESP include participant selection, the methods used to test ESP, lack of control during experimentation, and the progression of ESP research.
The most basic criterion in conducting experiments is to have a randomly selected sample that is representative of the general population. This inclusion of variable subjects ensures the generalizability of the phenomenon and encouraged replicability. Historically Rhine’s research with ESP has disregarded this criterion, and parapsychologists continue to do so today. Many subjects are recruited after they initiate contact with the Rhine Research Center, which is encouraged by the institute especially if an individual has had past experiences with parapsychology, such as reporting incidences of telepathy and clairvoyance (Rhine Research Center, 2013b). The participants self-select into the research, are biased towards the research topic since they believe they have had pseudoscientific experiences, and are often not kept blind to the purpose of the study, thus biasing performance towards positive results. Reviews have also shown that subjects who are psi-hitters are repeatedly used in ESP studies (Lilienfeld, 1999; Milton & Wiseman, 1999). Due to the lack of random selection, it is unlikely that the findings would be generalizable to the population, let alone replicable by others who do not self-select in to these studies.
Zener cards have been the most-often used methodology in ESP, although historically they have been one of the worst designed methods. Flaws include their composition (in the earliest studies, the cards were translucent which allowed subjects to see the design on the opposite side), and the design of the deck (five symbols that are each present five times in the deck present a twenty percent chance of a successful guess by chance, which is much more liberal than a regular deck of cards), (Diaconis, 1978; Lilienfeld, 1999). There is also the influence of probability if the participant keeps track of which cards they have predicted earlier in the deck; believing that they have already answered “circle” five times prevents them from guessing it a sixth time, which changes the probability of them guessing correctly in subsequent trials if they have guessed incorrectly in early trials. Zener cards continue to be used in ESP research today, and despite their improvement in design of the physical card, the statistical odds have not changed.
Another mark of science is stringent control over as many aspects of the design as possible, hence the dominance of experimental designs, specific hypotheses, and experimental control over extraneous variables. The only hypotheses that follow from ESP are that people, or people who possess psychic abilities, should demonstrate precognition, clairvoyance, and telepathy; none of these have been reliably demonstrated in a scientific study that incorporates controls, and many accounts of ESP are unsubstantiated, anecdotal claims (Milton & Wiseman, 1999). This lack of reliability in performance prevents further hypotheses involving greater specificity, which is known as progression and is a mark of science. Even if parapsychology gives the appearance of progression, it is further bullied by the problem of extraneous variables. Many of Rhine’s original studies have been critiqued for experimenter bias, participant bias, and misuse of statistical analyses. These problems manifest themselves through subtle cues to the participant as to which card is being held, having participants self-select into studies and not controlling for beliefs in parapsychology, selecting participants that are psi-hitters, and using the wrong statistical techniques during analyses, leading to false positives (Diaconis, 1978; Kellogg, 1936; Lilienfeld, 1999; Milton & Wiseman, 1999). While these problems can occur in scientific disciplines, the studies with these problems are usually screened during a peer-review process of the scientific community, and steps are taken in subsequent research to avoid repetition of avoidable problems. This is not the case with ESP; these mistakes continue to plague published research and are faults of both the experimenter and the alleged peer-review process of parapsychology journals. Neither has taken initiative to fix these errors, and as such progression is deterred.
The incidence where scientific rigor is employed, participants have been shown to perform at rates around chance, whether it be Zener cards or the Ganzfeld method. Despite the lack of evidence, parapsychologists manipulate past faulty experiments and present them as new research, thus spurring the production of the parapsychological journals. The appearance of publications and a formal society suggest progression, but it is simply because of fanatics and people invested in, whether that be financially, emotionally, or morally, the study of ESP. As previously stated, parapsychology continues to build on a broken foundation which is created by many faulty components. Actual scientific disciplines reject this practice by improving the faulty aspects of experiments, such as reducing bias and sampling randomly, by implementing a stringent peer-review process that is cohesive with related scientific disciplines, by developing more accurate and reliable methodology, and also by rigorously training professionals and encouraging diversity in academics so that the scientific process is consistent across all domains and disciplines. Parapsychology has yet to make those efforts, further distancing it from the realm of science.

Why ESP is a Pseudoscience

ESP is no longer worth pursuing in the academic field of science due to its short-comings inrelation to scientific theory and the basic paradigms of philosophy of science. Consider Popper’s theory of falsifiability; “the scientific status of a theory is its falsifiability,” (1963, p.4). This means that confirmatory results should only be considered when they are expected a priori by specific predictions, the theory should be refutable and forbid certain outcomes, researchers should honestly make an attempt to refute their hypotheses, and ad hoc assumptions should not be used to maintain theories that have been refuted. Popper also defines a pseudo-scientific method as “a method which, although it appeals to observation and experiment, nevertheless does not come up to scientific standards,” (p.1). Comparing these criteria with ESP research shows that ESP is not a science, but rather a pseudoscience, especially given that Popper’s guidelines have been critiqued as too liberal for science by other philosophers such as Thomas Kuhn and Gustav Hempel. Firstly, researchers for ESP do not make meaningful, specific predictions about ESP before hand, partly because there is no theoretical framework for it and also because past research has not been consistent enough to base predictions on. Secondly, studies present ESP as essentially irrefutable. Criticisms and flawed studies are met with excuses and promises for progress from the ESP community, instead of stringent testing and, eventually, conceding that ESP is not a reliable effect. ESP studies also do not forbid certain outcomes, or rather they do (for example, the person should perform at better than chance odds) but then ignore negative results. As with the prediction dilemma, it is difficult to make specific claims on what should or should not happen when the paradigm in question in unreliable and vague. General claims about ESP are also irrefutable; how can one be certain that the person who scored slightly above chance was employing ESP and not simply coincidentally above chance? Researchers seem to treat the theory as refutable, but when it is refuted they disregard the criticism and continue with a broken paradigm. Given this, it is not surprising that ESP studies do not reflect honest attempts to refute the theory. The sampling is below the scientific standard, the controls used in studies are weak, and meaningful review of the phenomenon is avoided. In some cases, it is possible that researchers alter data or misuse statistical procedures to write a successful paper, which is not the goal of science. Lastly, many researchers offer post hoc reasoning for negative results, and such problems are usually repeated in other studies despite peer-review and public access to the information. The most dangerous post hoc reasoning possible is that the environment was not conducive to parapsychology, or that the experimenter’s disbelief in ESP caused negative results. Not only are these pitiful attempts to save face, but they are irrelevant to the scientific method. Somehow, the ESP community continues to accept such claims as legitimate and continue to make the same mistake over again.
Popper’s standards are not the only ones negated by ESP. The Bayesian approach to confirmation is based on probability and can be applied to odds of ESP research (Chalmers, 2013). Zener card designs are clear examples of applied probability and can be compared to the Bayesian theorem; as discussed previously, performance with these cards above standards odds of chance are not reliably shown. Just as Bayes rejected Nicod’s criterion of positive results not implying confirmation of a hypothesis, the same should be expected with ESP even if performance were to be above chance, that even if ESP were shown to work in some studies it does not imply that the hypotheses are correct based on the given theory.
Many parapsychological disciplines, including ESP, also disregard Duhem’s problem of third variables or alternative causation both when they receive positive and negative results (Duhem, 2013). In general, ESP fails to control and account for third variables, and has been shown to do so even in their most controlled studies (Lilienfeld, 1999; Meehl, 1956). While Duhem argues that failure to see positive results may be due to methodological flaws, there has been rigorous research done by legitimate psychologists that has repeatedly found ESP to be ineffective. The idea of absence of evidence not being evidence for absence in regards to ESP is a mental trap, and by the time negative evidence has accumulated in a variety of studies, it is time to accept ESP as a lousy pseudoscientific theory as opposed to a discipline that has a problem with third variables.

"It's Bad For Ya" (George Carlin, 2008)

As with all pseudoscience, there is a negative cost associated with prolonging belief in ESP for both the general population and the scientific community. Such negative costs include knowledge, credibility, finances, and time.
Encouraging ESP research is problematic because we base our knowledge on the scientific method. By accepting ESP, an individual then inherently disrespects the scientific method and the past science that opposes parapsychological claims. For lay individuals, there is no obvious problem with this, however society tends to encourage knowledge and truth for the sake of knowledge and truth. ESP is an affront to scientific truth. For those that are professionally or academically concerned with science, accepting ESP is paradoxical. One cannot accept scientific theory and believe that ESP is a scientific endeavor because doing so would imply that one does not actually respect, or perhaps understand, scientific theory.
As mentioned above, it would be paradoxical for one to accept scientific theory as an appropriate method of knowing about the world and accept the study of ESP. The scientific community has agreed that ESP is pseudoscientific, and since this is the case any belief in ESP is considered a loss in credibility due to the lack of strict adherence to the scientific method. This is harmful not only to one’s profession, but possibly to friendships other members of the community. This is because most people view belief in the “extrasensory” to be either deluded or stupid, and rightfully so. While credibility is a crucial aspect of one’s life, the financial loss of belief in ESP is just as harming. While government-recognized funding agencies boycott parapsychology, citizens are encouraged to donate to parapsychological agencies and associations that put the finances towards ESP studies. Not only is this a misuse of public funds, but it is a waste considering the past negative results. Lastly, time spent repetitively studying ESP is time that is not spent on more conducive research. If these researchers are genuinely interested in science and have the abilities, their talents ought to be used on more progressive and productive areas of science. It may also be the case that researchers, those working with participants that genuinely believe that they have psychic powers, are encouraging mental illness in subjects by encouraging an effect that is typical of severe mental illnesses. If these claims are taken seriously by researchers and encouraged indirectly through research, the mental health of the subject could continue to deteriorate and the client feel that the other scientists, such as medical professionals who do not believe in seeing the future, are wrong because another scientist (one who studies ESP) says that the effect is OK.


ESP research and concepts lack a scientific foundation both in theory and in practice. It joins astrology in the sense that it is treated as pop psychology and delivered to the public as science by organizations with vested interests (Thagard, 1978), however it suffers similar pitfalls in method and design, and cannot be treated as science.


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