Extrasensory Perception (ESP)

Lecture 7ParapsychologyPaul Staples

Overview

What is ESP? Telepathy Clairvoyance Precognition and Retrocognition

Experimental evidence Restricted-choice experiments Free-response experiments

The process approach Summary

Learning Objectives

This session will enable you to Give a reasonable definition of ESP Categorise the various types of ESP Understand the nature of the experimental evidence

available Appreciate the criticisms and counter-criticisms of

some of the findings Appreciate the difference between resticted-choice

and free-response scenarios Recognise that there are other considerations, such as

those suggested by the process approach

What is ESP?

Extrasensory perception (ESP) is perception that occurs independently of the main physical senses (sight, hearing, touch, taste and smell or, indeed, perceptual processes such as proprioception)

In some ways the term is vague but it is generally used to imply a source of information that is unknown to modern science

ESP can be divided into a number of sub-categories

Telepathy

For telepathy the source of information is another person’s mind

The principle requirement of telepathic transmission is that the information transfer cannot be explained by any known physical process

Often the demonstration involves information transfer over large distances

Unlike physical information transfer, telepathy is not subject to the weakening of the signal the further you move away from the source

Clairvoyance

Clairvoyance is similar to telepathy except that the source of the information is an object or event rather than another mind

As well as clairvoyance, we can propose clairaudience where the source of information is auditory rather than visual

Clairaudience is an alleged psychic ability to hear things that are beyond the range of the ordinary power of hearing, such as voices or messages from the dead

Precognition and retrocognition

If the clairvoyance or clairaudience concerns things in the future or the past the these are referred to as precognition and retrocognition respectively

Dreams have sometimes been related to precognition and characters like Nostradamus are famous for their precognitive visions

Retrocognitions can be about recent events (e.g. the perpetrator of a recent murder) or distant events (e.g. historic events)

Retrocognition is different from past life regression

Experimental evidence

ESP experiments fall into two broad categories Restricted-choice experiments

The receiver must make a decision about what is being transmitted from a small set of known possibilities

Zener cards are an example of restricted choice stimuli Free-response experiments

Here the sender will choose an item from a large but finite set of possible stimuli

The receiver is not told anything about the nature of the chosen stimulus

The remote viewing you participated in was a free-response set up.

Restricted-choice experiments

In the 1930s one of the most prominent places for ESP research was the Rhine laboratory in America established by J B Rhine

A typical study from that era is the Pearce-Pratt experiment

Typical card-guessing experiment – using zener decks (25 cards, 5 target alternatives, MCE = 5)

74 runs conducted over 37 sessions Sender and receiver (Pratt and Pearce) in

separate buildings (100 or 250 yards apart)

Restricted-choice experiments

Watches synchronised so that when Pratt turned over a card, Pearce made a guess

Both recorded their sequences Hits counted independently by Rhine Rhine present with Pratt during last few

sessions Mean hits per run was significant at p < 10-22

No likelihood that results were due to chance

Restricted-choice experiments

Hansel (1961) criticised the study by suggesting that as no-one was with Pearce during the sessions, he could have gone out of his room and looked through a window at Pratt’s cards.

This could not be shown to be wrong until 1967 when Stevenson was able to locate the original blueprints

However, on scrutinising the official and unofficial reports of the experiments there are inconsistencies in the number of hits recorded

Restricted-choice experiments

Pratt-Woodruff experiment (1939) 2,400 runs across 32 volunteers Mean hit rate was 5.21, p < 0.00001 However, the result attributable to only 5 of the 32

volunteers Pavel Stepanek

Library clerk from Czechoslovakia Took part in 27 studies across 18 investigators Was discovered through his ability to state whether

the white or dark side of a thin piece of cardboard was face up inside an opaque envelope

Performance level at around 57% correct, p<10-6

Restricted-choice experiments

Bill Delmore Yale law student in the early 1970s Unusual in that he had vivid visual imagery, frequent lucid

dreams (knowing you are dreaming) and a high degree of confidence in his psi abilities

520 playing cards mixed and placed in desk drawers Experimenter picked a card and without looking at it placed it

in an opaque folder 46 runs of 52 trials each (2392 trials) Delmore had an excess of exact hits! For exact hits p < 10-30

Delmore was also successful on other tasks

Free-response experiments

Remote viewing (RV) experiments Puthoff and Targ were the first to do this in the late 1970s They worked with Uri Geller whom most parapsychologists

quickly became suspicious of Their first work was with Pat Price, a Californian police

commissioner Target location chosen from a pool of 100 Target observed for 30 minutes Price asked to verbally describe and to draw the location Nine trials Independent judge taken to each site and then asked to rank

the drawings from 1 to 9 according to their similarity to the site Seven were ranked first at the correct site (p < 10-4)

Free-response experiments

Critics of these experiments are Marks and Kammann (1980)

They suggested that there were biasing clues in the transcripts of the verbal descriptions

Now some of the judges failed to correctly identify matches

Also, only the most successful trials were chosen for publication and this falsely increased the statistical result

However, there have been a number of successful RV experiments reported in the literature

Free-response experiments

Ganzfeld Experiments We have already talked about the Ganzfeld

procedure It has become a popular method of testing ESP Honorton (1978) claimed that 23 out of 42 ganzfeld

experiments had yielded statistically significant results

Successful results came from 9 independent labs Taken as a collection of results the evidence seems

quite impressive

Free-response experiments

In the 1980s, Hyman criticised the findings on several grounds

Experiments had small numbers of participants and may only have been submitted for publication if the data were significant

Scoring procedures varied widely across the studies In experiments using multiple conditions only one had

to be successful for a positive claim to be made One-tailed tests were used even though psi-missing

outcomes (the other tail) were considered as successes (i.e. a success was recorded for a score significantly different from chance whether it be better or worse than chance)

Free-response experiments

Honorton countered these criticisms by recalculating the results in line with the criticisms

The level of success was not compromised even though the success rates reported had been too high

Other criticisms, such as one concerning the quality of the randomisation process, were conceded by Honorton

Free-response experiments

Overall, it would seem that the studies have been fairly rigorous even though improvements could have been made

However, this is no more true here than it is in all other areas of human research

Whilst the apparent ESP demonstrated so far may not compel one to accept ESP, the evidence does point to there being something worth further investigation

The process approach

All of the research considered so far is concerned with trying to establish proof of the existence of ESP

Other research tries to increase our understanding of psi anomalies

Some may consider this approach premature until the proof has been verified

The process approach

The process approach looks at the following aspects that need to be considered Cognitive processes – right hemisphere, cognitive capacity. Belief in ESP – sheep and goats Personality traits – extraversion/ESP correlation The experimenter effect – experimenters get significant

results in psi experiments because of…experimenter error, psychology and psi hypotheses.

It attempts to explore the degree to which these factors interact with ESP

There is not time to explore these aspects further here

Summary

We have seen that there is some convincing data concerning the possible existence of ESP

The data are not yet at the stage where they provide unequivocal proof of the existence of ESP