But this book did another thing: It gave the field a frame-work of organization, showed how psychical research could be conveniently renamed and defined, suggested a system for its various problem areas and indicated where ESP belonged in it all. I do not see how I could do very much better today although if I were rewriting the first chapter I would trim it somewhat. For one thing our problems today are not primarily in terminology, due perhaps partly to this bit of organization introduced at that time.
It is also worthwhile to compare this summary of experimental parapsychology made in the early thirties with the picture of the field today. Since I laid myself out rather broadly in the commentary chapters at the end of this book, there are a great many points for comparison. In a general way, the succeeding decades have rather confirmed the leading points of that commentary. What are some of these confirmations? The position taken that ESP was just not the sensory type of perception is one of these. Similarly, the nonphysical hypothesis of ESP has been considerably strengthened, and by the introduction of wholly new types of evidence as well. The unconscious level of operation has been more and more confirmed. The impression of the importance of motivation on the part of the subject is likewise strengthened. The lack of any association of ESP with ill health, mental or physical, has been firmed up strongly over the years. Also, the basic unity of ESP in its different phenomenal effects, telepathy and clairvoyance, has been further supported. It has been even extended, so that now it is in order to think of one basic parapsychical interaction between subject and object represented in ESP and PK (psychokinesis). We think of parapsychical phenomena as manifestations of this underlying reversible interaction between the person and his environment—extrasensory on the one hand and extramotor (PK) on the other.
Some of the tentative suggestions I made in 1934 have been strengthened. One of these emphasized the primary role or initiative of the percipient or receiver in telepathy tests. I stressed this "going-out" or active participation by the receiver as more likely than the view of a passive part in the transfer. Similarly, my hints regarding the energetic character of ESP have become bolder over the years, to the point where I would now say it makes little sense to talk about parapsychical operations without the assumption of a distinctive energy.
Where was I wrong in 1934? Had I known then what I now know about the evidence of ESP in animals, I would hot have made the suggestion I did, even though tentatively, on the evolutionary position of ESP. It is now much more likely that ESP is something the animal kingdom possessed long before man himself evolved; but we must leave to future research a firmer answer to this important question area.
I thought too, perhaps naturally enough, that when a subject persisted in avoiding the target in ESP tests and giving significantly negative deviations from the expected average instead of the positive ones he was supposed to give, this meant he was unconsciously negative in his attitude. But, in the light of later studies, I have now abandoned this hypothesis of negative motivation for "psi missing," as it is now called. I am not, of course, saying that there is never negative motivation but that it is not the more general explanation of these significantly negative deviations.
LATER DEVELOPMENTS
What has happened since the publication of this book in the science of parapsychology? I will outline the main advances briefly under the heading of New Methods, New Phenomena, and New Events.
New Methods: First, I will speak of mathematics. Al-though the binomial method used throughout this book is still the principal method of appraising results, there are slight changes. Instead of using the probable error, we now use the standard deviation as the "yardstick." Also, when we combine critical ratios, by the use of the root-mean-square method we use the chi square tables. But there are a number of other convenient and useful methods of evaluation of test results now available to the parapsychological worker. The most useful of these are assembled in Chapter 9 of the introductory test book by Dr. Pratt and myself, called Para-psychology, Frontier Science of the Mind. Para-psychologists in this country have had no serious trouble over mathematics because of the extraordinarily generous cooperation of mathematicians; to give only one example, The Journal of Parapsychology has had throughout most of its existence two highly qualified mathematicians as statistical editors.
New test methods have naturally had to follow upon new problems. In the main, however, the methods have been built on or around the skeleton of test structure used throughout this book. The use of five targets, whether or not the standard ESP symbols, the run of twenty-five trials, and certain elemental test precautions in testing and recording have become fundamental. Again, these methods are summarized in Chapter 8 of the textbook just mentioned. Specific techniques had of course to be developed for the investigation of precognition, psychokinesis, and other distinct effects to be measured. There were also new telepathy tests to meet difficulties raised when precognition was introduced into the picture. For some of these more complicated methods the original articles in The Journal of Parapsychology should be consulted.
One main advance has been the introduction of test design to make it impossible for one of two experimenters to make a mistake without its being caught by the other. The two-experimenter test procedure is, of course, only used when the more conclusive or crucial type of experiment is conducted. A large range of research needs to be carried out under relatively free exploratory test conditions, much as most of the research reported in this book was done. For a discussion of the two levels of methodology, see Chapter 2 of the book. Parapsychology, Frontier Science of the Mind, mentioned above.
Heavy emphasis in present-day research in this field is on the provision of appropriate psychological conditions, aimed at favoring good ESP test performance by the subject. (Pratt and I have a chapter—no. 7—on this in our book.) Free exploratory conditions permit a wider range of possibilities for this important condition. Better controlled conditions can then be introduced when the stage is reached at which it is worth while and important to increase the precautions against counter explanations.
Another of the latest turns in research methods is the new look at spontaneous parapsychical occurrences. This is not for their value as evidence of psi but for the research clues they furnish. Some idea of this case approach can be had from Dr. Louisa E. Rhine's book. Hidden Channels of the Mind, and from her article in The Journal of Parapsychology.
New Phenomena: ESP of future events was next. In fact, at the time this book appeared in 1934, the Duke Laboratory had already begun its precognition tests, the first on record, and these had yielded positive results. It is true; many years of work were needed before the findings seemed sufficiently well-confirmed to warrant publication. They were not even mentioned in my first popular book on the ESP work. New Frontiers of the Mind, which came out in 1937. However, by 1947, in The Reach of the Mind, I did review this development and by that time felt justified in taking a fairly confident stand on this phenomenon.
Then followed PK. The evidence of psychokinesis or the direct action of mind over matter had just begun to accumulate in the Laboratory when the book was released in the spring of 1934, but it was not until nine years later (1934) that the first article reporting the findings appeared in The Journal of Parapsychology. This work, too, based on the ability of the subject