Extra-sensory Perception (ESP)

Introduction

What is ESP? How can it be measured? ESP, or extra-sensory perception, according to Encyclaepedia of the Unexplained by Richard Cavendish, is the "...reception of information through means other than the known senses...". The "known senses" being the five we use every day, which are sight, taste, smell, touch and sound. According to the book, "...Clairvoyance, precognition and telepathy are subtypes of it...". 

The ESP experiments at Duke University

In the 1930's, parapsychologist, Joseph Banks Rhine - or, as he is better know, J.B.Rhine - conducted some experiments in his laboratory at Duke University, involving extra-sensory perception (ESP). Indeed, it was Rhine himself who was the person to first coin the term ESP.
    According to http://archived.parapsych.org/members/jb_rhine.html, the Duke experiments on telepathy, clairvoyance and precognition "... used specially designed cards called Zener cards. About the size of regular playing cards, these cards were composed of decks of 25 cards, with each card having one of five symbols on one size: a cross, star, wavy lines, circle and square. Zener cards Under various experimental conditions, subjects would attempt to guess these cards. Out of each deck of 25 cards, 5 correct guesses were expected by chance. Using exact binomial probability calculations, it is possible to determine how 'improbable' it would be to guess an excess number of cards correctly. In one set of experiments, 2400 total guesses were made and an excess of 489 hits (correct guesses) were noted. The statistical probability of this outcome is equivalent to odds of 1,000,000 to 1 (against chance) and thus show significant evidence that 'something occurred.'"
     The results of these experiments were staggering; according to the website, by 1940 "...33 experiments had accumulated, involving almost a million trials, with protocols which rigorously excluded possible sensory clues (e.g., by introducing distance and/or barriers between sender and receiver, or by employing precognition protocols (i.e., where the target has not yet been selected at the time subjects make their responses)."

       According to http://dukemagazine.duke.edu/issues/111209/depqa.html, when he first began his ESP experiments, Rhine "...started with a test of simple playing cards. He began with children, but then moved on to Duke students. It was basically a simple test: "Can you tell me what playing card I'm holding?" without seeing it. And he found that they could.

The 25 Zener, or ESP cards

He was using a regular deck of playing cards, and he found that people had certain biases—they would guess certain cards more often than others because they were very familiar with a regular deck. So he had a psychologist, Karl Zener, design him a set of cards with completely different symbols. And these are the ESP cards that a lot of people are familiar with, the ones with the wavy lines, a star, a box, a circle, or a cross. Using these cards, he repeated the test with students and found that they were again able to tell him what symbol was on the cards without seeing them."

             The cards which Rhine and Zener, a hypnotist, used are known today as 'ESP' or 'Zener' cards. Rhine and Zener, according to the website,  "...refined the experiments over the years—first, they separated the student and the experimenter with a screen. Ultimately, they were in separate rooms, and the tests were done double blind, so that even the person conducting the experiment didn't know what symbols were on the cards.

The other experiments that they're known for are tests in psychokinesis, the ability to move objects with your mind. Again, the test that they used was a very simple one—rolling dice. They would see if the students could influence the roll of the dice. The experimenters would use their hands and throw the dice against the wall, but, later on, they were using machines to roll the dice, so it would be more random and the experimenter could not be accused of influencing the roll.
And they found, again, that the students did seem to have some ability to influence the roll of the dice, but the effect was a lot weaker. It's not like somebody can go to Las Vegas and win a billion dollars with this ability. It was infinitesimally small."

Scratch project

 
The research

    The Rhine Research centre was established by J.B.Rhine and the organisation is still running today. J.B. Rhine is considered a 'founding father' of modern parapsychology. According to http://www.rhine.org/who-we-are/history.html "When Joseph B. and Louisa Rhine joined Professor William McDougall at the newly founded Duke University in 1927, the field of investigation into psychic phenomena was known as psychical research. At that time psychical research was mainly concerned with working with mediums in the search for evidence of an afterlife. J.B. Rhine recognized that answering the survival question depended first on investigating the ability of the living to gain psychic or psi information by other than sensory means (telepathy and clairvoyance), an ability for which he used the term extrasensory perception (ESP). Rhine began testing Duke students with specially designed cards to study ESP and later used dice machines to study psychokinesis (PK), the movement of objects by mental intention alone."

  

The Ganzfeld method

 
A technique called the Ganzfeld was being developed and researched as a means of 'blocking out the physical senses' and was being used in dream telepathy research. There were some people who were unhappy with Rhine's experimental procedures and so they began doing ESP experiments using the Ganzfeld.