DUKE U FRIENDS OF DUKE UNIVERSITY LIBRARY GIFT OF ret: J... Bs... Rone in 2022 with funding from Duke University Libraries ia \ up i) | Le | Py Bs a j ' if } \ y , = me ‘4 i https://archive.org/details/parapsychologyfr1957rhin Us : , PARAPSYCHOLOGY Frontier Science of the Mind PARAPSYCHOLOGY FRONTIER SCIENCE OF THE MIND A Survey of the Field, the Methods, and the Facts of ESP and PK Research By J. B. RHINE and J. G. PRATT Parapsychology Laboratory Duke University Durham, North Carolina CHARLES C THOMAS ¢ PUBLISHER Springfield + Illinois + U.S.A. CHARLES C THOMAS * PUBLISHER BANNERSTONE House 301-327 East Lawrence Avenue, Springfield, Illinois, U.S.A. Published simultaneously in the British Commonwealth of Nations by BLACKWELL SCIENTIFIC PUBLICATIONS, LTD., OXFORD, ENGLAND Published simultaneously in Canada by THE RYERSON PRESS, TORONTO This book is protected by copyright. No part of it may be reproduced in any manner with- out written permission from the publisher. Copyright 1957, by CHARLES C THOMAS * PUBLISHER Library of Congress Catalog Card Number: 57-10999 Printed in the United States of America Foreword ek ARE many indications that the time has come to provide a convenient one-volume summary of present knowledge about parapsychology. Most urgent is the need among busy profes- sional people for a clear, concise statement of the known facts of this new field of science, just how the researches are carried on and what general advance has been made in relating the new findings to older branches of knowledge. Outstanding among the audience we have had in mind are the various professional groups connected with medicine and the psychological and social sciences and practices. This book was undertaken as a result. There are other professional groups, too, for whom the volume was intended as a handbook of essential information on the sub- ject: The teacher, for example, or minister or field worker in anthropology should, we believe, find it as well suited to his purpose as the psychiatrist or dermatologist or clinical psycholo- gist. In a word, the competent, mature inquirer, whatever his professional field, should consider that the book was written for him. Finally, these pages have been written, too, with the coming need of a college textbook in mind. Two university requests for such a text have recently been received, and with the present prospects of the growth of parapsychology, others are anticipated. More popularly written introductory books on parapsychology have been published in recent years. The titles of most of them may be found in the literature cited in the book. Younger stu- dents and nonprofessional readers making their approach to para- psychology may find it advantageous to read one or more of these other works by way of introduction. This book is, of course, not meant for our long-experienced fellow workers in parapsychology, nor even for the well-read highly informed student of the field who knows most of its scien- tific literature at firsthand. Likewise, it should not be considered as intended to answer and satisfy completely all the questions the Vv vi FOREWORD extremely skeptical reader might raise; we cannot take space for all that, especially now that it is largely of historic interest only. Those who begin here can, however, readily find the way to the supporting literature with the help of the frequent references provided. The plan of the book is simply to state the established facts and to offer in the text references to the main publications that cover the researches concerned. Only the main references, however, are given. None but the research parapsychologist would need the rest, and he well knows how to find them himself. This book, rather, is designed to be read and consulted by those who do not already know the field but who wish, to some extent at least, to enter it with proper information at hand. Each section and sub- section is labeled, identified and indexed as clearly as possible to make the search for needed items a quick and easy one. The essential features of method and apparatus are photo- graphically illustrated. The procedures, both methodological and evaluative, are given to an extent that should serve the purpose for all but the professional parapsychologist himself. If there are shortcomings encountered, we want to know about them for cor- rection on revision, and if information is lacking that the reader cannot himself find with the help of the available references, we will welcome direct inquiry from readers. We are indebted to our publisher, Mr. Charles C Thomas, for the suggestion that this book should be written. Our greatest obli- gation, of course, is to our fellow-workers in parapsychology who have given us the findings these pages review. We are especially grateful to those colleagues who have helped with the manuscript: Dr. R. J. Cadoret, Dr. Louisa E. Rhine, Dr. R. H. Thouless, Dr. T. N. E. Greville, Dr. J. A. Greenwood, Mrs. Sally Feather, Mrs. Farilla David, and Mrs. Joan Walker. We have, of course, to hold ourselves responsible for whatever inadequacies the book may still reveal. J.BR. J.G.P. Parapsychology Laboratory of Duke University Durham, North Carolina Contents Page SRO le pa se Se a ee SES IN Vv PART I PRESENT KNOWLEDGE Chapter Pe aHEMIOR SCIENCE YS es Se a a SS a 5 Definition of the Field, 5; Subdivisions, 7; Relations to Other Areas, 10; Clarification of Terms and Concepts, 12; 2. OsjyectivE ResearcH METHODS ............ 17 Introduction, 17; The Two Stages of Scientific Method, 19; Exploratory Methods in Parapsychology, 20; Methods of Verification, 30; Methods of Distinguishing Types of Psi, 39. S..) Lae PAGTS ABOUT Pst AND ITs TYPES... 0 62003 6. °% 3. 45 The Evidence for Psi, 45; The Case for Clairvoyance, 53; The Problem of Telepathy, 54; The Case for Precog- nition, 56; The Case for Psychokinesis, 59. a) *Pse-anp THE PrHysicat, WORLD... ... 2 2)... @ .. 66 First the Facts, 66; And Then the Implications, 72. Sead IESYCHOLOGY (OF: PSTe 2 oc eeepc ks ie we 4h whe 78 Psi is Normal, 79; The Place of Psi in Personality, 85; Conditions Affecting Psi, 93. 6. Pst RESEARCH AND OTHER RELATED FIELDS ....... 101 Psi in Practice, 101; Psi in Psychiatry, 105; The Place of Psi in Education, 107; Anthropology’s Contact with Psi, 109; The Biology of Psi, 111; Physiological Explorations in Parapsychology, 113; The Psi Frontier on Medicine, 115; Parapsychology and Religion, 118; The Philosophy of Psi, 122. viii PARAPSYCHOLOGY PART II TESTING TECHNIQUES 7. PsyCHOLOGICAL RECOMMENDATIONS FOR Psi Testinc . . . 131 Right Psychological Conditions Essential, 131; In- fluence of the Experimenter, 131; The Psychological Needs of the Subject in Psi Tests, 133; The Experi- menter-Subject Relation in Psi Tests, 135. 8. Some Basic Pst Tesr Procepunes . ... .«. «see 139 Introduction, 139; Exploratory Psi Tests, 140; Con- clusive Test Methods, 156; Summarizing Comments, 167. 9. SratisticaL METHODS... « . « s+ «+ ss 170 Introduction, 170; Evaluation of a Total Score, 172; Evaluation of a Difference Between the Scores of Two Series, 175; Some Uses of the Chi-Square Test, 177; Other Methods of Statistical Evaluation, 180; Criterion of Significance, 185. Last oF TABLES . . 5 6 0e sae ee te ne 189 SoME SIGNIFICANT EVENTS IN PARAPSYCHOLOGY ........ 199 Grossamy . ... 0) nose 2 ee 205 Name Inpex i... wd ede 2 ee a 211 Illustrations Page Decline in scoring rate within...testsof PK. ....... 49 Quarter distribution of hits on the record page and set... . 61 Dice used for comparisons in PK tests... ......... 71 EReeaE Or sise) Bieter |. 5b) ee fae gs ite ee Gee 83 Effect of attitude upon ESP test performance. ........ 92 EEE RBE Sets 50. gs.) URS vue ke SE PAR ie 142-143 PenIRE Me ORRRCREEES fo VE gees ie aD eae NT eerie ae Ae eh 148 Placement test or psychokinesis .) 6.0 2. a 155 Screened touch-matching test of ESP... ......... 160 PK test for target face with machine-thrown dice. . . ... . 165 PARAPSYCHOLOGY Frontier Science of the Mind PART I Present Knowled ge ' Chapter 1 A Freld of Science I. Definition of the Field i SCIENCE of parapsychology began with the interest aroused by the reports of spontaneous human experiences and events that are familiarly known as “psychic.” These puzzling phenomena have never been claimed by any of the conventional branches of science, and until comparatively recent decades they had been ignored by all but a few scientists. Yet records of such occurrences have come from peoples of all cultures and periods and, simply as reported human experiences, they would manifestly have some proper claim on the attention of science. Moreover, they raise some very distinct and important questions for experimental in- vestigation. At this point, however, these odd types of experi- ences are mentioned only to help in identifying the subject matter of the new science with which this volume is concerned. It should from the very beginning be made clear that the phe- nomena with which parapsychology deals are all, without excep- tion, events of nature. In other words, the field of problems be- longs entirely to natural science. As the next chapter will indi- cate, the observations and experiments are dealt with strictly in the established manner of scientific inquiry. Accordingly, what- ever comes out of the investigations of this field belongs, just as in any other branch of science, to the body of organized knowledge known as natural law. More specifically, the observations and events dealt with in parapsychology—parapsychical phenomena—are associated in some central way with living organisms, as distinguished from inanimate matter. To limit the area still further, this science deals only (as far as we know) with behaving organisms; not, for ex- 5 6 PARAPSYCHOLOGY ample, with bacteria or grains of corn except as these might be involved incidentally. Thus parapsychology belongs not only in the realm of biology but it is localized in the sub-division of psy-— chology, the science concerned with persons, personality, or per- sonal agency within the living world? What, then, identifies a psychical phenomenon as parapsychical? It is an occurrence that has been shown by experimental investiga- tion to be unexplainable wholly in terms of physical principles. It is, in fact, the manifestly nonphysical character of parapsychical phenomena that for the present constitutes their only general identifying feature and marks them off from the rest of general psychology. This does not, of course, alter the fact that the data of parapsychology are natural. As a matter of fact, our concept of what is “natural” is built up out of just such discoveries of science as they are made; accordingly it goes on growing, and will continue to do so, with each added bit of knowledge. It is now clear that, contrary to some of the limiting philosophies that cur- rently prevail, nature extends beyond the domain of purely physi- cal law. The distinction of these parapsychical occurrences from physics is not, however, an absolute one. Rather, they usually involve physical events or objects, either as stimuli or as effects. But there is always some distinct point at which a completely physical inter- pretation is manifestly inadequate. To illustrate, the direct in- fluence of human volition on a moving object without the use of any kind of physical energy to achieve the effect would constitute a phenomenon for parapsychological study. Or again, an individ- ual may obtain knowledge of an event occurring beyond the range of his senses and his reasoning abilities. If there should be no transfer of physical energy from the event to the individual, no sensory function could convey the knowledge and the experience would be parapsychical. Every science necessarily begins with an area of “unknowns,” with a group of interrelated phenomena that challenge explana- tion by the already existing sciences. At the earliest stage of a new scientific field it is usually hard to define the aggregate of the little-understood phenomena well enough for useful discussion. But parapsychology has already passed this stage, and we may A FIELD OF SCIENCE 7 now characterize it as the branch of inquiry which deals with non- physical personal operations or phenomena. This definition of parapsychology, while sharp enough for prac- tical purposes, is naturally limited to the present stage of knowl- edge, as indeed all terminologies must be. It is strictly the para- psychology of today, the physics of today, and the psychology of today that must be dealt with in the working concepts of the times. There is, thus, a certain fluidity and an unavoidable tentativeness to the boundaries and definitions used in this branch of science just as in any other department of knowledge. II. Subdivisions The main divisions of the field of parapsychology are derived from the two broad types of observed phenomena with which it deals: extrasensory perception and psychokinesis. These phe- nomena, like all psychical (psychological) occurrences, whether spontaneous or experimental, consist either of reports of subjec- tive experiences on the one hand or of observed physical effects on the other. In the experiences of extrasensory perception which make up the more familiar division of parapsychical phenomena, knowledge is acquired in a special way—by a mode of perception that is independent of the senses. In one of these cognitive ex- periences an individual may seem to be looking upon a distant scene somewhat as though he were physically there. In such cases there is usually no difficulty in observing that information was received, although in other kinds of parapsychical experiences the individual may have indirect evidence of knowledge without conscious certainty of the fact or may be impelled to a certain course of action without at the time being aware of the reason for so doing. This use of the terms “knowledge” and “experience” to cover a wide range of responses to external events when there is no sen- sory basis is a concession to convenience; but from now on we can be more precise. Since the knowledge conveyed in a parapsychi- cal occurrence concerns events external to the subject, technically the mental process is properly called a perception. Since the senses are not involved (and, with no physical mediation from the 8 PARAPSYCHOLOGY object to the percipient such as characterizes sensory perception, they could not be) these cognitive phenomena of parapsychology are called extrasensory perception or ESP. The other main subdivision of the phenomena of parapsychology includes all those occurrences in which, again without physical intermediation, some personal influence produces a physical ef- fect. Such direct mental operation on a material body or a physical energy system is called psychokinesis or PK. This is the same as the familiar popular concept of mind over matter. These two main branches of parapsychology, the phenomena of ESP and PK, appear to parallel the system already familiar to general psychology, the sensorimotor relations between subject and object. In both sensory perception and ESP the subject re- sponds to or shows some degree of knowledge of an external event. And on the side of the reaction of the subject to the object, both in the already familiar motor responses and in PK, the individual mentally exerts an effect upon some part of the physical environ- ment. The one fundamental difference that is most obvious is that in his sensorimotor relations with the objective environment the subject relies upon energies that have been already identified’ and to a large extent understood by physicists. In ESP and PK, then, the subject interacts with the objective environment in a way for which there is no physical explanation and no acceptable physical hypothesis. Rather, the evidence in- dictates that the psychophysical interoperations of ESP and PK in- volve a basis that is not as yet known or observed except through the aftereffects shown in the experiences and experiments with which parapsychology is concerned. Not only has no intermedi- ating process or principle yet been discovered but, thus far in the functioning of either ESP or PK, no specialized organs of reception or motor function have been localized. Thus it may be said that between the ESP-PK system and the sensorimotor system there is a general parallel of mind-matter relation even while there is also what seems at this stage of scientific inquiry to be a very funda- mental difference. The relationship between ESP and PK is still only partially un- derstood. The view that has gained widest acceptance is that the two operations involve essentially the same sort of psycho- A FIELD OF SCIENCE , 9 physical interaction. The end results of the two processes or functions—if they are really different—are, of course, manifestly distinct effects. In the one case the result is an experience related to an external situation; in the other, an observable physical effect. Whether the occurrence be a spontaneous one or the result of an experimental test, these differences are phenomenologically dis- tinct enough to justify the use of the two subdivisions, extrasensory perception and psychokinesis. But as the reader becomes familiar with the nature of these capacities and their way of functioning he will find it easy and convenient to use a general term to desig- nate the whole range of parapsychical phenomena, and for this the Greek letter psi has come into general use. This is a device of convenience and does not imply that it is known that there is only one basic underlying type of process. ESP phenomena of three general types are commonly recog- nized. These distinctions, too, are only partial and tentative ones. In fact, these three general classifications of ESP effects are mere descriptive terms that were applied to the phenomena as they came to be identified in the early stages of the developing science. But while they are comparatively arbitrary classifications, they have been so widely used in the literature and practice of the re- search that they are not likely to be abandoned for some time. The two most familiar subdivisions of ESP, telepathy and clair- voyance, were in general use long before the term “extrasensory perception” itself was accepted. Telepathy, originally defined as the transfer of thought from one mind to another without the in- termediation of the senses, is the effect which was most empha- sized in the early period of psi investigation and it has, there- fore, received the widest popular attention. In recent decades, however, the experimental work in parapsychology has been pre- ponderantly concerned with clairvoyance. Clairvoyance is de- fined as the extrasensory perception of objects or objective events, as distinguished from the mental states or thoughts of another person. As the science of parapsychology has advanced, the basic similarity of the processes of telepathy and clairvoyance has be- come more and more apparent. It now seems doubtful whether they are two different processes after all. At any rate, it would be difficult to offer any specific fundamental difference between 10 PARAPSYCHOLOGY the two types of manifestation of ESP except, of course, in the targets perceived—the one subjective and the other objective. The third category under ESP is generally called precognition. This is simply the perception of a future event by means of ESP. To qualify as a genuine instance of precognition an experience must refer to a coming event to an extent that is more than merely accidental; it must identify a future happening that could not have been inferred as about to occur; and, finally, it must refer to an event that could not have been brought about as a consequence of the prediction. For the present stage of parapsychology these four general subdivisions—extrasensory perception and psychokinesis, with the former further subdivided into telepathy, clairvoyance, and pre- cognition—serve well enough for the necessary exchange of ideas and the discussion of results. As will be seen in the later chap- ters these subdivisions which have been reflected in the spon- taneous psi experiences from which the branch of science arose have been confirmed by the experimental studies that have re- sulted. Thus far no other clear-cut subdivision has been found necessary or justifiable; and the impression is given that these four types of parapsychical phenomena are the result of a single under- lying psi function. In any case, a fundamental relation between the subject and the object that is in some degree nonphysical has been established. III. Relations to Other Areas The present distinction between parapsychology and general psychology is fairly obviously a temporary one. Parapsychical phenomena are distinguishable from the other phenomena of psychology merely by the fact that they can be shown to be non- physical in character. With regard to the rest of the more purely psychological processes there is no way of telling whether non- physical operations play any part. Some theorists in psychology have taken the position that all mental life is essentially non- physical; but this interpretation was made on philosophical grounds. What science itself will discover about the rest of the domain of psychology we need not try to predict. A FIELD OF SCIENCE ll ¥ : | The relation of psifto the world of physics and physiology is more clear-cut than its relation to general psychology. Here there _are demonstrable criteria of differentiation. The fact that psi functions so far show no limiting influence of space and time reveals a distinction that is perhaps the most fundamental yet encountered in the entire universe of knowledge. The evidence is now conclusive enough in parapsychology to leave no doubt that, so far as present concepts go, we are dealing with nonphysical principles and processes. Even so, the distinction is only rela- tively thoroughgoing. The psi function is in all instances the result of an interaction between an organism and its environment; and in the latter a physical system is always in some way involved. Even in telepathy, with a supposedly “mind-to-mind” transfer, there has in all verified instances been a physical brain coordinated with the sender’s thought. Science has not yet discovered enough about the relation of mind and brain to say how far the distinction can be carried between these two systems and whether the appar- ent dualism is anything more than a relative distinction. The occurrence of interaction between psychical and physical systems. implies to the logical mind a basic unity suggesting that the phenomena of parapsychology and physics are both of the same all-embracing universe. If so then a larger scope of reality is still to be disclosed than has been as yet revealed. Physics, then, is not unrelated to psi and its operation. We can say, rather, only that psi is not describable in terms of physical processes. , > |The extent to which psi is found to be a generalized capacity * among living behaving organisms will determine what and how significant its place should be in the larger field of biology. For the present this is a question under active research. Since psi is definitely a human capacity, at least, and since the nature of personality is fundamentally important to a wide range of human relations, a broad area of significant possibilities should be listed here if completeness in this outline of relations were to be required. It is particularly important to consider what differ- ence the establishment of psi as a human characteristic will make to the larger disciplines concerned with human society. The dis- covery in man of properties not attributable to physical law gives to the theory and philosophy of human relations a distinctly anti- 12 PARAPSYCHOLOGY materialistic quality that is revolutionary and far-reaching. For — religion it gives a scientific rebuttal to materialism; for ethics and mental hygiene it removes the road-block of mechanism; and for medicine, psychotherapy, and education it provides a scientific status for the common-sense concept that there is something in the subjective life of man that has distinctive principles of its own. It is safe to say that when the recognition of psi as a nonphysical component of human personality has occurred, there will hardly be any area of human relations untouched by the i of this generalization. IV. Clarification of Terms and Concepts ~~ * The term parapsychology was adapted from the German word, Parapsychologie, the most widely used of the European terms which identify the field. It means the same as the older English expression, psychical research, and the French, métapsychique. Psychical is an ambiguous word, being used in general psychology to mean “mental.” The popular use of the word psychic, while convenient and well-entrenched, has the same ambiguity. The prefix para added to psychology (and psychical) serves well enough the purpose of marking off a section of the general field of psychology for such time as the distinction is needed. But it is not to be applied loosely as a generally valid prefix for other similar uses in the field. For example, the terms paraphysical, para- physiological, paranormal, and the like, are not sufficiently clear- cut in their meaning to justify their use. Paranormal has a certain amount of current usage as an equivalent of parapsychical, but like its predecessors, supernormal and supernatural, it seems to carry the quite erroneous (and unintended) implication that psi phenomena are not a normal part of nature. Normal is itself a word of two many proper as well as improper meanings to be used reliably in terminology and definition. The term extrasensory perception which came to general use in 1934 has proved to be more useful than its alternatives, such-as super-sensory perception, ultra-perceptive faculty, paranormal cognition, metagnomy, etc. It has probably survived because it has fitted the need for a descriptive expression that implies no untested theory as to its nature. A FIELD OF SCIENCE 13 /The word telepathy came into use around the beginning of the century to describe what had been called thought-transference (mental telegraphy, etc.). It is redundant to use the modifying adjective mental to describe telepathy. Clairvoyance is perhaps the oldest term in general use in parapsychology and it has outlasted a number of expressions that were introduced to describe the extrasensory perception of objec- tive events, of which the following are the most common: lucidity, telethesia, cryptesthesia. Efforts to introduce related terms such as clairaudience and clairsentience have failed because the term clairvoyance is not limited to its etymological derivation, “clear- seeing.” ‘Psychometry has had a wide usage in parapsychology for what may more appropriately be referred to as token-object tests of ESP. (i.e., identification of people and events associated with an object by means of ESP). The term psychometry has an estab- lished use in general psychology in its proper sense of mental measurement, and it should not be abused in any parapsychologi- cal application. - The introduction of precognition to identify the ESP of future events logically suggested the term retrocognition for the ESP of past occurrences. However, there is no adequately verified psi phenomenon to which retrocognition itself may be applied. At the time of the introduction of psychokinesis there was a choice between it and the term telekinesis, mainly associated with physical manifestations connected with the claim of medium- ship. Telekinesis means “action at a distance,” and psychokinesis, “the direct action of mind upon matter.” The use of the latter term was preferred as more accurate and as more clearly having no limiting connotation of discarnate agency. A number of efforts have already been made to provide a sys- tematic general nomenclature for parapsychology. They have, however, all been premature and no such attempt has at best contributed more than perhaps a single accepted term or two to general usage in the field. Obviously the effective and accepted application of a systematized terminology will call for a well- organized rationale of the phenomena to be dealt with. But parapsychology has only recently reached the status of organiza- tion presented here. It will require a period of time for a - 14 PARAPSYCHOLOGY sufficient familiarization with this pattern of findings to occur before the field will need a more systematic set of descriptive terms. Parapsychology needs also to be distinguished from popular concepts connected with certain areas of practice or belief which are sometimes confused or associated with it. Occultism is one of these. This term designating the study of hidden arts or princi- ples does not apply to Tis sclestlic tyne of ampeoaclh Aaa y to the scientific type of approach that charac- terizes parapsychology. Spiritualism is another term that has been widely associated with parapsychology. Spiritualism, how- ever, is a religion, having for its central emphasis belief in the existence of a world of discarnate personalities supposedly able to communicate with the living, mainly through mediumship* They are also believed capable of manifestations such as hauntings and poltergeist phenomend. {a sort of rough-housing attributed to noisy spirits). As with all religious systems of belief, there are certain doctrines in spiritualism based upon the assumption of capacities that have not been verified by scientific method in parapsychology. The relationship of parapsychology to areas possibly involving its principles is, in general, something like that of a pure to an applied science area. There is the important difference, however, that in no instance in parapsychology as yet has such application grown out of preceding laboratory discovery. Certain of the terms more commonly associated with spiritual- ism have come into widespread popular usage; for example, the terms medium and mediumship. Strictly speaking, the term medium implies a theory of spirit survival and of communication of discarnate personalities with the living through the intermedia- tion of persons known as mediums. This is a doctrine in the Spiritualist faith and is not a scientifically established fact in parapsychology. It is, however, correct to say that the investiga- tion of the hypothesis of spirit survival and communication would be a parapsychological one. (see Chapter 6). The distinction between parapsychology and psychopathology ought to be made clear, since textbooks on abnormal psychology have often included them both without adequate distinction. There is no implication of pathology in anything associated with parapsychology; and, on its part, psychopathology has traced A FIELD OF SCIENCE 15 none of its causal factors to the domain of parapsychology (see Chapter 6). _ Hypnosis or hypnotism was for a long period of its history associated with psi phenomena, especially in its aspect of “som- nambulism”; but as the studies of both hypnotism and para- psychology have advanced, the independence of the two classes of phenomena has become amply clear. Similarly, the vaguely defined state known as (self-induced) trance has passed through a similar evolution; as have also the various motor automatisms (unconscious muscular movements) such as dowsing, automatic writing, and the use of the ouija board.~-Gradually, through ad- vancing understanding, the phenomena of parapsychology have emerged as distinct from these earlier associations and are now describable and demonstrable in their own characteristic properties. Additional Reading Eprror1aL: A proposed basis for choosing terms in parapsychology. J. Parapsychol., 9:147-149, 1945. EprrortaL: Pattern of history in parapsychology. J. Parapsychol., 17:247—-258, 1953. James, Wm.: The confidences of a “psychical researcher.” American Magazine, pp. 580-589, Oct., 1909. Loncg, O.: The university aspect of psychical research, in The Case For and Against Psychical Belief. Worcester, Mass., Clark Univ. Press, 1927, pp. 3-14. McDoveatt, Wo.: Psychical research as a university study, in The Case for and Against Psychical Belief. Worcester, Mass., Clark Univ. Press, 1927, pp. 149-162. McDoveatt, WmM.: Editorial introduction. J. Parapsychol., 1:1-9, 1937. Mourpny, G.: Parapsychology, in Encyclopedia of Psychology. New York, Philosophical Library, 1946, pp. 417-436. Murpny, G.: The place of parapsychology among the sciences. J. Parapsychol., 13:62—71, 1949. Myers, F. W. H.: Human Personality and its Survival of Bodily Death. New York, Longmans, 1954. Rung, J. B.: Extrasensory Perception. Boston, Bruce Humphries, 1934, pp. 5-14. 16 PARAPSYCHOLOGY Rune, J. B.: Introduction to experimental parapsychology, in Present- day Psychology. New York, Philosophical Library, 1955, pp. 469- 486. Rung, J. B.: Parapsychology, in The New Outline of Modern Knowl- edge. New York, Simon and Schuster, 1956, pp. 193-211. Rung, J. B.: The Reach of the Mind. New York, Wm. Sloane, 1947. Rue, J. B., et al.: Extrasensory Perception After Sixty Years. New York, Holt, 1940, pp. 3-21. Smewick, H.: Presidential address. Proc. Soc. Psych. Res., 1:7-12, 1882. Tuoutess, R. H.: Thought transference and related phenomena, in Proc. Roy. Institution of Great Britain, 1950. TyRRELL, G. N. M.: Science and Psychical Phenomena. New York, — Harper, 1938. Chapter 2 Objective Research Methods I. Introduction A FIELD of science should properly be judged on the basis of its methods of investigation. In parapsychology, however, as in any branch of psychology where there are subjective or mental factors and conditions to be dealt with, a consideration of the objective methods alone is not enough. As a matter of fact, there is even a question as to whether they come first in importance. But for the purpose of this book it will be advantageous to present the objective methods first and deal with the important considera- tion of psychological methods and conditions of experimentation later (Chapter 7). The reasoning is that an appreciation of the sound status of the facts of parapsychology should come first, and for that the objective methods are clearly of prior importance. After this first step is taken, then the shift of interest to other problems makes the psychological conditions the more important in their turn. By objective methods we do not mean only the specific testing techniques by means of which the investigations are made. The standardized test procedures generally used in the study of psi phenomena are, of course, an essential part of the methods; the main types of procedure are described in Chapter 8. Likewise, the mathematical techniques that play an important part in meas- uring the degree to which the experimental results exceed the level expected from pure chance are an essential part of the objective methods; they are given in Chapter 9. These descrip- tions of the more specialized techniques, while they are essential to research and clinical use, are not necessary here for an appre- ciation of the general way in which psi has been investigated. 17 18 PARAPSYCHOLOGY Thus, as we have just indicated, three major sections of what might be broadly considered as methods in parapsychology are considered in another section of the volume. This leaves for the present chapter the general program of how, in concretely describ- able fashion, research in parapsychology is done; how its questions arise; how, and how reliably, they are answered. (It should be said at the outset that because of the challenge of the findings of parapsychology, the research workers have a greater consciousness of method and of rigorous control than is found in other branches of science. The radical nature of the results have also made it necessary to develop a wider range of safeguards against error than in any other field. This is, however, altogether proper when revolutionary conclusions are drawn. Within reasonable limits such added precautions must be take A few people, it is true, have questioned whether it is possible for science to deal effectively and exhaustively with such non- physical functions as-are investigated in parapsychology. The very strangeness and elusiveness of some of the human experiences dealt with in this field tend to raise questions concerning the full adequacy of such methods. But we need only remember that physics itself, as well as other curricular branches of knowledge, have long been working at least partly with extrasensory phe- nomena—operations and effects that are clearly beyond the range of the sense organs. They are, of course, not connected with personality or mental life and, therefore, are not parapsychical; but, like psi capacities, they can be measured only by their indi- rect effects. Most of the researches in general psychology, too, depend upon this indirect approach. The general principle followed is that anything in the universe man will ever know about creates effects; and through these effects it can be indirectly studied, even if the process itself is beyond the range of the senses and even beyond reach of the instruments that so greatly extend the range of the senses. In theory, at least, it should be possible for science to investigate any real phenomenon, any true operation in the universe; and we can advance as far as we have the patience and ingenuity to go toward satisfying ourselves of its genuine occurrence. Moreover, if the first inquirers are able to describe their methods clearly as OBJECTIVE RESEARCH METHODS 19 they proceed, others, too, if they are prepared, can then follow the trail, confirm its existence, and improve or extend it still further. II. The Two Stages of Scientific Method A \Science has two fairly obvious general functions. One of these is its role of exploration or discovery, the turning up of new phenomena or ideas; the other is the task of verification or the making sure whether a claimed discovery or suggested hypothesis is valid. Both are essential, and one is as important as the other. Moreover, it is extremely important for worker and student alike to keep both of these two types of scientific inquiry in mind, and above all to keep each with its proper requirements in its proper place. This is not always done in actual practice. Many students of science who are mainly concerned with but one of these two stages of scientific inquiry tend to forget that there is another too. Some, of course, are largely unaware of methods as such; they are casually following a heritage of custom established by habit and routine. (The chief characteristic of the exploratory stage of scientific inquiry is that in it the explorer is permitted to range widely, venture freely, and look into everything that might be important to his interest without being burdened with too much precaution- ary concern. It is a more venturesome, a more extravagant phase of investigation. It is always a first stage, of course, but only because of the natural order of investigation. While it is obvious that without this exploratory stage there would be little or nothing for science to verify or establish, it is equally true that with it alone no results would ever be firmly established. On the other hand, the second or conclusive stage of research has very different characteristics. Its emphasis is mainly on reliability. The starting point is a claim or hypothesis to be put to crucial test and the first step is the drawing up of an experimental plan carefully designed to take all the alternatives into account. The testing itself must be done with constant vigilance to see that the requirements laid down in the plan are fully met. Equally important, perhaps, are the soundness of logic used in interpreting 20 PARAPSYCHOLOGY the results and the careful suspension of judgment regarding con- clusions until the accepted standards of science are met—standards of adequate experimental control, of extrachance(statistical) sig- nificance, and of independent confirmation by other investigators. The most common violation of good method, at least in parapsy- chology, lies in the much too ready confusion of these two phases of science—exploration and verification. For example, an over- anxious inquirer may (like a scout setting out with heavy battle equipment) attempt to carry the complex controls of verification along with him when he is setting forth on purely exploratory activities. Equally common is the reverse emphasis in which a research worker jumps to premature and unwarranted conclusions on the strength of what are no more than exploratory findings. He does not feel the need of waiting for the slow, firm test of crucial investigation. There are many variations of these familiar viola- tions of good procedure; they are not, of course, limited to para- psychology. As we have already said, however, there has been good reason for workers in this field to become especially conscious of methods and standards. III. Exploratory Methods in Parapsychology The ways of exploratory inquiry in parapsychology are sub- stantially the same as those used in other comparable fields. One of them is the elementary method of studying reports of excep- tional spontaneous occurrences and generalizing from such a study to an hypothesis that can be put to test or a claim that can be examined by means of other methods. This is the case-study method. A second method of exploration, identified as the pre- liminary individual test, is adapted to the introductory study of special persons such as, for example, those whose behavior or experience suggests unusual psi powers. The third way of screen- ing projects for more conclusive investigation by trying them out on a small scale in a preliminary way is called the pilot test method. Fourth, much valuable exploratory work is done by going over the data of earlier experiments. Re-examined with fresh problems in mind, these records often contribute new in- sights not glimpsed during the original investigation. This is the method of re-examination. OBJECTIVE RESEARCH METHODS 21 In all of these four methods (the principal ones that have been followed) the purpose is to make a discovery, at least a tentative one; this becomes a new hypothesis for further investigation. Thus the end point of an exploratory investigation is a new and impor- tant question, one that deserves for its reliable answering the more refined treatment of a crucial test. A brief discussion of each of these methods will give a better idea of how most of the research in parapsychology has actually been done. As in any field of science, more time and effort are generally needed on the explora- tory stage of a problem than for the conclusive stage of research. A. Case-Study Method Originally, parapsychology as a science began with reports of spontaneous personal experiences of unexplainable nature. In the early studies emphasis was placed upon the need to authenti- cate such cases as allowed careful checking on the reliability of reporting. It became evident, however, that even elaborate effort in substantiating them did not furnish sufficiently unquestionable evidence to warrant a conclusion. The hypothesis was too revolu- tionary. Experimental methods had to be introduced for that purpose. The case study is by its nature primarily an exploratory method; it would be difficult if not impossible to convert it into a crucial method of verification. At the present stage of parapsychology, the case method pro- vides a very important source of suggestions as to the nature and properties of psi as it functions spontaneously. The research worker can, with advantage (beginning either with an appropriate case collection already available or by making one of his own) ask his questions of Nature as represented in these experiences. If it be a specific question as to how psi operates spontaneously, and if the collection be suitable and the question answerable, he should be able to get a tentative answer. This trial-answer or hypothesis may be impressively evident or it may be but slightly indicated. No matter how strong the appearance of support, however, the tentative new idea is still based on the reports of human experiences which cannot be sufficiently validated to per- mit a scientific conclusion to be reached. 22 PARAPSYCHOLOGY But there is some preliminary testing of an idea that can profit- ably be done within the case method itself. A question or hypothesis raised from one collection of cases can be checked against another or even more than one. A confirmation from a second large collection would considerably strengthen the status of the hypothesis, though it would definitely still not provide con- clusive verification. To mention only one possibility of weakness, the two collections might have a common defect, perhaps one in- herent in the cultural influence affecting them both or in the method by which the two collections had been assembled. But such support as a second collection might give would go far to warrant the large effort which experimental verification calls for. In this way could be worked up the pressure of confidence and challenge needed before the much greater outlay of research time and other resources demanded by the conclusive test would be undertaken. It is not, in fact, justifiable to undertake the more crucial stage of testing until the exploratory build-up has at least answered the principal objections that may be raised and has developed a reasonably probable case. This much can be done by the case method when it is used to best effect. Collections of psi cases will, of course, vary according to col- lectors and also according to the instructions issued regarding the types of cases desired. It is best to make a new collection and to secure broad coverage of types; in older collections the persons reporting the cases may have been given too selective instruc- tions. In the same way it would be wise not to require any specific standard of reporting or authentication since thereby many cases for which there could be no corroborative support possible would be excluded. Since the purpose is to discover Nature’s own way of demonstrating such phenomena, it would be defeating the purpose of exploration to rule out at the collec- tion point, just because they seemed less impressive from the point of view of evidentiality, any types of cases that could have bearing on research problems. In recognizing the tentative status of the case study results, the explorer can be relieved of misplaced anxiety over the reliability of a report. Case study methods involve much that need not be considered here at length. They depend, of course, on the logical judgment OBJECTIVE RESEARCH METHODS 23 exercised in making analyses. If a question is asked of a case collection, it needs to be clarified and the possible answers stated clearly enough for definite understanding by others. The stand- ards of analysis need to be defined so plainly that another worker can follow and, if desired, re-analyze the same material. Results must, of course, be stated when appropriate in quantitative form as percentages or ratios and, when justified, the distributions may be tested for extrachance significance by a chi square method (see Chapter 9). The cases referred to thus far were those of the spontaneous type occurring to the individual, but in a more general way the same method of exploration applies to all nonexperimental items of observation that can be grouped or collected for general com- parison and analysis. Instances of observation among professional workers in related fields such as anthropology, psychiatry, and religion and among such practices as dowsing and mediumship should be studied in their preliminary stages by essentially similar exploratory methods. B. Individual Screening Method Probably the exploratory practices in widest use are those of examining and screening individual subjects, either for participa- tion in more conclusive experimental work or for a more elaborate exploratory program. Most commonly in such preliminary tests the investigator is dealing with a person who believes on some basis or other that he is gifted with psi capacity and wishes to know the extent of his ability. The contact between him and the experimenter may have arisen as a result of the individual’s own curiosity over his spontaneous experiences or he may have been referred to the research worker by a teacher, psychiatrist, or minister. In any case, a widely adaptable preliminary test method is needed for this purpose, one that will lend itself to a variety of conditions while still affording a reasonably accurate estimate of the ability concerned. It has been greatly advantageous, indeed, to have certain stand- ard methods of testing available, methods with an already existing frame of reference into which results may be placed for compara- tive judgment. The widespread use of the standard ESP card 24 PARAPSYCHOLOGY test, with a five-symbol pack of 25 cards developed at the Duke University Parapsychology Laboratory, makes it more efficient to follow an adaptation of this method; a wide basis of comparison is automatically provided. The fact that there are five possible choices makes 20 per cent success the level of scoring to be ex- pected from pure chance. If for any reason the subject to be tested has an expressed preference, the five symbols of the stand- ard deck (star, circle, square, cross, waves) can be replaced by a set of five colors, five animal pictures, or any other suitable set of items. In fact, there are advantages in these local adaptations. But there again availability has the advantage; and the standard deck of ESP cards mentioned above has not only been the most widely used in the ESP researches of the last 25 years, but it is at present the most conveniently available.*® Above all, however, the method to be used needs to suit the subject’s interest and preparation. If, for example, he shows any hesitation to use a test that makes possible definite scoring (and mathematical evaluation), a preliminary test could use other target material (e.g., pictures cut from magazines). It is wise to start with whatever the subject believes is the best for him. The change to other and better conditions can be made later, once success in scoring has been demonstrated and the subject’s confi- dence established. Should a subject fail in preliminary tests, it would be much better for him to do so on tests which he has been fully ready to accept and approve. If he does fail persistently from the start and no variation of conditions over a number of sessions can induce success, there is nothing to do but discontinue; only if, and as long as, he is giving a moderate show of successful scoring is it profitable to try to improve and advance the test conditions. Once, however, a subject shows special ability under free, in- formal conditions, the next step is to introduce safeguards. This should, for psychological reasons, always be done with a subject's full approval and cooperation. With continual improvement of * To keep the copyrighted standard cards available, authority to distribute them is restricted in the U.S.A. to Haines House of Cards, Norwood, Ohio, and its distributing agencies. OBJECTIVE RESEARCH METHODS 25 conditions the point will be reached at which the experimental controls will be sufficiently rigorous to meet the full requirements of verification. When that point is reached, the proper procedure is to go right into it as if no real distinction were involved. The line between advanced exploration and initial verification is, in any case, an arbitrary one. The subject himself is usually the better for not having the strain of being told he is facing a crucial test. In general, any neglect of the delicate psychological condi- tions that psi subjects require for effective demonstration is waste- ful. We assume, however, that Chapter 7 on the psychological conditions for psi tests will be taken into account with this one. It is essential, too, that the experimenter have some knowledge of what to expect from a subject—that is, how to judge the rate of scoring. He needs to know as the tests progress how well his sub- ject is doing if only to know when to advance or to change over to the next stage. While it is important to allow the new subject to begin with any preferred condition he may have in mind and to allow an amply successful demonstration on this level before add- ing precautions, if a subject has no set ideas and no predilections as to methods it is of advantage to start with conditions that rule out as many of the conceivable errors as possible. With that in mind, we recommend a clairvoyance test rather than one for GESP or general extrasensory perception. A GESP test makes no at- tempt to distinguish between telepathy and clairvoyance (for ex- ample, the sender looks at the target card during the trial). A clairvoyance test requires only one subject, instead of the two needed wherever telepathy may also be involved. It also elimi- nates for the experimenter any concern over possible sensory com- munication between sender and receiver. Even if the subject prefers GESP, he may be persuaded or challenged to try clairvoy- ance after some initial success with the other method. If not, and the GESP test has to be used to start with, it is important, even on the exploratory level, to advance the test procedure so that two rooms are used, with the sender in one and the receiver in the other, and with the connecting door closed. But with clairvoyance test methods the advance to adequate precautions can be more rapid and the evidential value of the results accordingly greater. If the subject is not hesitant, the test 26 PARAPSYCHOLOGY can begin with the cards screened entirely from all sensory con- tact, even in the very first test. Then, with the experimenter keep- ing records of all scores for a full appraisal and with a method of double witnessing (by subject and experimenter) of the card recording and scoring, the method should be sufficiently safe for this preliminary order of testing. The basic requirements for safeguarding the procedure and for evaluating the results will be found in Chapters 8 and 9. It should be possible to develop testing devices that would be so adaptable to diverse situations and individual needs that (when they are properly used) the most free and informal ESP test would be fully safeguarded. Progress toward this ideal is highly desirable especially since there are many clinical, educational, and other practical adaptations of the ESP test that are awaiting such a development. But it is no less necessary here than elsewhere to emphasize again that the requisite psychological conditions dis- cussed in Chapter 7 would also have to be met or the test could not be considered in any real sense an ESP test at all. C. Pilot-Study Method The third exploratory procedure in parapsychology makes use of a small trial research preliminary to a larger, more thorough one. It already has had a fair amount of use and it has been of great value to the field. It is especially needed to offset the tend- ency of overenthusiastic experimenters to plunge into elaborately designed projects right from the start. Some investigators who have been successful in other stages of scientific work assume, unjustifiably, that they will naturally succeed, too, in conducting psi experiments in what they assume to be a comparably proper and effective manner. They reason that since others have suc- ceeded they should expect to do so, and that since they have done competent research in other areas they should be expected to get results in parapsychology as well. But this is to overlook the many uncontrolled variables that are usually present in the psychologi- cal experiment and are especially likely to cause trouble in in- vestigations with so elusive a capacity as psi. It is in just such a case that a small pilot experiment can serve a very useful purpose—in fact, a number of purposes. The experi- OBJECTIVE RESEARCH METHODS 27 menter can first of all satisfy himself that he has what is required as an experimenter to bring out psi capacity in the subjects with whom he expects to work. He can at the same time assemble a selected team of subjects and settle many other initial questions involving experimental conditions. If a preliminary experiment is clear-cut and indicative he then will know what to do on the main project. If the pilot study is discouraging, more preparation or modification of the design is in order and perhaps further pre- liminary researches. It is, of course, important to keep in mind that the pilot experiment is definitely exploratory and that, what- ever its results, they are to be considered apart from the major project which it serves to introduce. One of the main values of the pilot study method in parapsy- chology springs from the need in this new branch to fend off wild theorists who approach the field with an unduly speculative bent. These rationalists would start off on an ambitious program to demonstrate their theories. They are usually difficult to persuade to try out first, on a preliminary scale, the wholly unsupported expectations they have built up. There is little to be gained from these impulsive attempts to launch a full-scale conclusive research project at their early stage of investigation. The pilot test stands ready to help the researcher, whether beginner or professional, to fit his experiments more effectively to his project. D. The Re-examination Method Fourth in the types of exploratory methods in general use in parapsychology is that in which old data are re-examined for other purposes than the original investigators had in mind. After an experimental series has been evaluated and reported for what it was intended to do, the author or another worker has in many in- stances had reason to re-examine the data in search of the answer to a different question from the original one. Many of the leading developments of the last quarter century in parapsychology owe their origin or support to this device of incidental exploring. The method is more than merely a search among old records for overlooked significance. It follows a more or less systematic course, in broad outline much like that of the case-study method. The researcher in need of an answer to a question turns toward 28 PARAPSYCHOLOGY whatever relevant available data he can find. He might be, let us say, asking whether the scoring rate in PK tests falls off in the course of a run (or column), as it does in ESP. Why should he trouble to carry out a new experiment to explore this possibility when there are files of old data to examine? Thus the old material, when it could answer the question, has often acquired a later value which its original producer never anticipated. It is true the first discovery in such a case would have only the tentative value of any exploratory finding. Almost immediately, however, the research worker may “predict” (that is, reasonably infer) that a similar result would be found in a comparable batch of old data still unexamined; and if this new program is well planned and properly handled, the magic line of verification itself can be crossed in the very next stride. This possibility of a quick changeover to a method of crucial test is one of the greatest values of this method. As we stated, there has been a very productive reclamation program in parapsychology. If we keep in mind that the takeoff by this reclamation method is always an exploratory research, we shall not make undue claims for its results until further (predicted ) reclamation verifies the first result. E. Methods for Clinical and Other Practical Uses A broad category of methods remains that, while not exploratory in the sense that we have been using the term, is comparable in many respects. These might be called clinical or practical methods; that is, ways of adapting psi tests to particular situations involving professional service in other areas than parapsychologi- cal research. Suppose, for example, that a clinical psychologist or psychiatrist needs to test a patient’s belief that he is especially endowed with a psi capacity. This somewhat resembles the situa- tion in which the Individual Screening Method described above is used preparatory to a more controlled research. The purpose, however, may be entirely subordinate to some such objective as diagnosis or treatment, and the standards required should be those which the professional practitioner will need to have for his — purposes. For such needs, whether they arise in connection with patients or in anthropological field studies, or in educational projects in- OBJECTIVE RESEARCH METHODS _ 29 volving special children, or in any other of the many possible situa- tions in which the question of unusual mental powers may arise, the general recommendation might be much the same. In a word, the adaptation of the standard testing techniques can, until special- ized modifications have been developed for a given clinical pur- pose, be managed in much the same way as exploratory testing of other individual subjects. The same relative care will be needed as in all psi testing to see that psychological conditions are properly met and to avoid imposing upon the subject to be tested a too artificial method or one he does not adequately understand or fully accept. Indeed, the rule should be rigidly imposed on the would-be experimenter to meet the subject's requirements as fully and carefully as if they were actually objective in character. Standards of the clinical or practical tests may be laid down by the professional worker himself according to the needs of his situation. At one extreme they could be as high as those used in crucial tests. But for general use at the bedside, in school, or in field situations a somewhat rough and ready test will be found more suitable and all the precautions not specifically needed may be dropped. Counterhypotheses to psi that have never had any real support in fact (as, for example, involuntary whispering on the part of the agent in a test involving telepathy), and which have been given an exaggerated importance only because of the controversy over ESP, can profitably be forgotten in practical testing. This and the special precautions against possible errors in recording may safely be left to the more controlled researches in parapsychology proper. Those who wish to apply the methods to adjacent problem areas will in any case naturally make such modi- fications of method as they themselves feel are warranted by the conditions and demands of their purpose. For this purpose wide ranging clinical adaptations of testing techniques are necessary and entirely in order. The four main exploratory methods just described were not de- signed by a logician; they just grew into usage and survived be- cause they proved successful. There are certain inconsistencies and overlappings that could bother the meticulous thinker a little. For example, the concept of the Pilot-Study Method could be 30 PARAPSYCHOLOGY stretched in principle to include the Individual Screening Method. Also, the Re-examination Method can be so quickly converted to a fully verifying procedure that to single out the first stage as ex- ploratory and then call the second verification (even though it may be a mere duplication) may seem a bit arbitrary. It is better, however, for the present to take these introductory fact-finding procedures as they are, since they are working successfully, and allow refinements of consistency and classification to develop with continued use and free discussion. There is certainly no crucial need for logical consistency since the methods are productive. Bringing them into explicit focus as we have done may, we trust, help both toward further clarification as well as more extensive use. No absolute distinction marks the transition from exploratory research to the second stage of method to which we now turn, that of verification or establishment. Rather, the transition is first of all a change of emphasis in the objective or purpose of the research worker. He need not always change his actual test procedure; though he probably will. So great, however, is the consequence of the altered goal of the new stage that a very different tempo and tone of research develops. The stress shifts completely from venturesome search to cautious assaying, each in its turn playing an essential part. IV. Methods of Verification The scientific establishment of any fact is admittedly a relative matter. One’s acceptance of a given finding or result often de- pends, for example, upon his personal attitude or philosophy. Whether one is conducting the research himself or only appraising a published report of it, he may reach a decision regarding the conclusiveness of the result without realizing the degree to which his mind was made up in advance. Accordingly, the candid ex- plorer would do well to bring into conscious perspective at the beginning any assumptions or prejudgments of the problem he can discover in his approach. Otherwise, he might be undertaking the investigation with an attitude that would require for his ac- ceptance that it turn out in a definite, limited way; and if it did not, he would be prone to reject the results on some ground or OBJECTIVE RESEARCH METHODS 3l other. There is even danger in a psychological experiment that such an attitude might so influence investigation that accuracy would be affected. In general, it is exceedingly questionable whether any experiment is worth doing until the investigator him- self is psychologically and philosophically prepared to take the consequences seriously, whatever they may be. We shall, therefore, assume that for a conclusive experiment we have an experimenter prepared to accept the results in an objec- tive manner. What kind of methods, then, are needed for the crucial task of verifying an hypothesis in parapsychology? A. Statistical Evaluation First, there is the requirement of sound measurement. In para- psychology this has to do with the estimation of significance with respect to chance. So long as psi capacity is in need of investiga- tion, there will always have to be provision to deal with chance as a possible explanation of results. In a word, statistics is needed in any branch of science for the investigation of functions not yet fully understood and controllable at will. Accordingly, when de- signing the scope and size of the experiment, it is necessary to take thought and record in advance just what means will be used to evaluate the results. For most problems of parapsychology, for- tunately, standard methods of applied statistics serve very well and there is little need for the novel and distinctive in this aspect of the field. The use of the principal methods has been expressly approved by both individual and group authority in statistics. These main techniques are described in Chapter 9 (as well as in the textbooks on statistics listed there). The test procedures that have been most widely used have been chosen and developed partly with a view to making evaluation comparatively easy. For the ESP researches the techniques in- volving testing by means of cards have been most commonly relied on, and the use of dice in the PK research has so far dominated that branch of the inquiry. In the ESP investigations the require- ment that there be a reasonable approximation to a random series of targets (card order) has been sufficiently well met to serve the needs of statistical theory by shuffling the cards and following end 32 PARAPSYCHOLOGY with a thumbnail cut. But the card order may, for special pur- poses, be made up also on the basis of tables of random numbers. In the measurement of the significance of rate of success in the tests, it has for the most part been adequate to use the oldest known procedure in parapsychological statistics as a yardstick. This method takes account of the total number of successes made in a given number of trials. It accurately estimates the number of hits to be expected on the theory of chance and finds the devia- tion of the hit total from this mean chance expectation. This deviation is then measured by means of (divided by) the standard deviation (SD); the quotient is the critical ratio (CR), a value which may be converted by means of the standard normal prob- ability integral table to an equivalent probability. Thus an esti- mate is made of the likelihood that results as different from chance expectancy as those in question would occur in a pure chance series. This is the measure by which the investigator knows whether or not his results are acceptably significant; that is, may reasonably be classed as nonrandom events. The ease with which the theoretical standard deviation is de- rived and the wide applicability of the method to the whole area of research in parapsychology for which standard methods of test- ing have been devised have done much to organize the field and to unify research activity within it. Results of the different re- searches can now be properly compared, combined, and, in gen- eral, treated in a systematic manner. B. Experimental Precautions The second basic requirement of a definitive research in para- psychology brings us to the aspect of experimental safeguards, and to the most important of these, the insurance that, in a crucial ESP test, there be absolutely no possibility of sensory communication. If a test is to be at all crucial, there is no excuse for using conditions that leave the question of sensory cues as one to be answered by judgment or interpretation. The possibility of sensory cues can conveniently be eliminated in a card test of ESP, especially in a clairvoyance test; it is much easier in that type of ESP test than in one either of pure telepathy or one that allows for the possibility of telepathy (GESP). If OBJECTIVE RESEARCH METHODS 33 there is no special reason for including telepathy, therefore, the test should by all means be carried out without a sender or agent present who is aware of the card order. Almost all of the difficul- ties that have arisen in controlling against sensory cues have come up in tests of GESP. It is obviously a simple matter in a clairvoy- ance test to screen a pack of cards entirely from a subject’s view, and such screening is necessary if a test is to be conclusive. With an ordinary opaque screen large enough to rule out any possibility that the subject might see around its edges, the pack of cards can be conveniently handled by the experimenter under adequate conditions of control. Watchfulness against sensory observation of the target in reflecting surfaces or through crevices is unneces- sary if, in addition, the experimenter “plays his cards close,” that is, keeps the target card always in a guardedly safe location behind the screen and face down. A number of modified clairvoyance testing techniques involve some elaboration of this simple screened card test. The cards may be enclosed in opaque envelopes or boxes that are then sealed, or there may be greater distance interposed between the subject and the cards by using different rooms, or even different buildings or geographic areas. Again, in addition to the calling techniques just described are those known as ESP matching techniques, tests in which an unknown card is matched against a set of “key” cards containing one of each type of symbol. The order of these latter may be either known or unknown by the subject. The various modifications are not different enough in principle to call for dis- cussion. The main techniques themselves are given in Chapter 8. If a research project involves telepathy, the requirement for a conclusive test calls for two rooms right from the start. Such separation will call for a method of communication between the tworooms. This should be a one-way method permitting only the receiving subject or percipient to signal the agent when he is ready for the next trial. All sensory communication from the agent would be suspect and it is necessary to go to considerable length to rule out the possibility of communication, deliberate or un- conscious, on the part of an agent in an adjoining room. If the distance can be considerably increased, it would be an added safeguard; if two people well known to each other are acting as 34 PARAPSYCHOLOGY sender and receiver, steps should be taken to eliminate the possi- bility of the use of concealed devices of modern radio communica- tion. It is always advisable, too, in attempting a conclusive test of GESP to have the order of the cards recorded before the pack is turned over to the agent, and to require that the percipient indi- cate or record his responses in silence, allowing no possibility that the agent could, in hearing that the percipient’s call scored a miss, shift the order of cards in such a way as to make the trial a hit. It is a particular advantage of the standard precognition test that all problems relating to the danger of sensory cues are auto- matically eliminated. This advantage has even tempted some experimenters to use the method in an exploratory way, since all that is needed is to hand out a record sheet and ask the would-be subject to fill in the column with what he anticipates will be entered at the checking stage in the card column opposite. There is, of course, a question whether many subjects are psychologically prepared to undertake a test in precognition at so early a stage of acquaintance with psi testing. In the standard tests of psychokinesis there is, likewise, no prob- lem of sensory cues; but there is a somewhat comparable one in the need to eliminate the possibility of error due to physical im- perfections in the dice or in the use of skilled methods of handling or releasing them so as to influence their fall. These problems have long since been adequately solved in a number of different ways. Any inequalities in the dice are, for example, adequately compensated for by the use of all the different faces of the die to an equal extent as the target objective. It has also been found possible in a variety of ways to avoid the risk that the subject may use trick throws to influence the fall of the dice in PK tests. One way is to require the use of a dice cup with a sufficiently roughened interior and also deep enough to prevent the application of manual skill to the roll of the dice. It has, likewise, been found practical to release the dice by electric switch, allowing them to fall from a V-shaped container onto a prepared (walled and padded) table. Likewise, electrically driven, rotating cages have been used which allow the dice to roll from one end of a long cage to another, giving sufficient time for them to come to rest at the lower end and allow observation and recording. At this point a photographic OBJECTIVE RESEARCH METHODS 35 record can be made as a part of the automatic operation of the apparatus. C. Care in Recording A third general requirement for a proper experimental verifica- tion in parapsychology concerns the making of adequate records of the results. All the data of an experiment must be recorded in such a way as to eliminate any possibility of error that could pro- duce spurious results. For this purpose, the ideally careful ex- periment ‘needs to be set up in such a way that the responsibility is shared between two persons qualified by training and selection to produce a faithful record, shared in such a way that no error made by either one could go undetected. This is referred to as the two-experimenter plan and its application to the various types of experiment might briefly be reviewed. The two-experimenter plan in a simple clairvoyance experiment of the type already described may be managed in the following way: The record pad presented to the subject for the recording of his responses has a carbon inserted for duplication. The packs of cards to be used in a given run have been recorded in advance with one copy of the record in the possession of a second experimenter who may or may not be actually present in the experimental room at the time the test is being conducted. At the end of the run the subject is instructed to turn over his duplicate to the second ex- perimenter or it may be inserted in the slit opening of a locked box prepared for the purpose (by the second experimenter). Then the first experimenter who is conducting the test can proceed to check the run with the subject participating, using the copies which they have of the card and call records. The second experi- menter has his own copies of the records for safekeeping and for a wholly independent check. In this way, while errors could still be made, they could not be made in a way that would produce extra- chance effects without being caught. There are, of course, many modifications of this two-experi- menter method. One of these that is simpler in its routine and is widely used consists of loading a target sheet of symbols in a heavy, carefully-sealed manila envelope. The experimenter who does this keeps a carbon copy of the target sheet. The other 36 PARAPSYCHOLOGY experimenter asks the subject to register his responses on a record sheet (complete with carbon and a duplicate call sheet) attached to the outside of the envelope, responses intended to duplicate as far as possible the symbols on the target sheet enclosed. The experimenter will need to be present throughout unless the sealing is entirely adequate. He then takes the unopened envelope to the second experimenter and in the presence of both the envelope is opened. The checking is carried out independently by the two experimenters, one working from the carbon sheets and the other from the originals. After complete agreement is reached on the results, the score totals are entered independently in the record files of each experimenter. It is no great tax upon the intelligence of an experimental team to design or modify the standard test procedure so as to make it virtually impossible for the two experimenters, unconsciously or otherwise, to overlook errors of recording, checking, or scoring. To apply the two-experimenter practice even to GESP tests is not difficult (speaking now only of the aspect of recording) especially when the card order is recorded in advance with a copy going to each experimenter and with the percipient’s responses being re- corded in duplicate. In precognition tests it is as simple as with tests of clairvoyance. The comparable precaution in precognition testing is to have the selection of the target order, as well as the whole checking operation, done throughout as a joint operation by the two experimenters with each retaining the full score record for his own file. It is somewhat better still to arrange for duplicate records both of targets and responses and to have independent checking. Applying the two-experimenter plan to the PK tests is somewhat more awkward because it tends to clutter up the experimental room with the presence of an additional person. Two observers recording the fall of dice creates an impression of top-heavy em- phasis on results that may be disturbing to the atmosphere of the test. Where photographic recording is possible one recorder, with the film record for a second check, can provide adequate control against errors. If two recorders can operate without interfering with the subject, the records should be made in silence and with OBJECTIVE RESEARCH METHODS 37 the record of each recorder invisible to the other during the test. This insures the independence of the two records. D. Precautions Against Deception A fourth type of requirement for sound verification might be found in the consideration of precaution against deliberate error. This is an unusual addition to scientific method, but it is called for largely because of the exceptional character of the hypotheses being tested. Also, some of the associations psi capacities have had with practices in which deception was common make it easier than in most researches to suspect that the subject might have deceived the experimenter. Accordingly, it is advantageous, if not necessary, to give special attention to this requirement. It is true, if all three of the requirements already listed have been fully and carefully met, it would ordinarily be impossible for the subject to practice any trickery; but it is possible to add certain supplementary safeguards that would further reinforce those precautions. In precognition tests, however, no further control against fraud is needed. In clairvoyance tests, too, the complete exclusion of deception by the subject is easily managed by the use of a two-experimenter plan. In psychokinesis, likewise, if the use of a rotating cage is adopted, or any plan that eliminates the sub- ject’s handling of the dice (and, of course, he is not recording his own results), subject trickery is ruled out. With GESP and pure telepathy, precautions have to be elaborate and have to be adapted to the special needs of the experimental situation. This method- ological problem is often taken too lightly; as we have said, GESP is the hardest psi-test procedure to control adequately against error, especially error due to deception. The safeguarding of the experiment against possible irresponsi- bility on the part of the experimenters themselves has been made a point for discussion in parapsychology,* though it seldom is in other branches of science. This is a consequence of the revolu- * In the most recent flare-up in the long controversy over parapsychology, G. W. Price (Science and the supernatural. Science, August 26, 1955) suggested that deliberate fraud on the part of the investigators is the explanation of experiments that cannot be attributed to error or incompetence. His article initiated a contro- versy that was carried on at length in the January 6, 1956 issue of Science, as well as in a symposium on the topic in the Journal of Parapsychology for December 1955. 38 PARAPSYCHOLOGY tionary character of its findings and the novelty of the field. It is the general practice in the sciences simply to suspend judgment about a new finding until adequate confirmation of a given experi- ment has been reported by other investigators. Just how much confirmation is needed for a discovery each may judge for himself. It depends a great deal on how unexpected the finding is. But under the circumstances unusual precautions have been taken in parapsychology to add safeguards against possible error by the experimenters themselves—error of either a deliberate or an un- conscious type. That was the purpose of the two-experimenter plan. It is not practicable, however, even in parapsychology ex- periments, to require more than two experimenters for a given project, and that is where the line has been drawn. Only in a few instances have three been assigned, but with too many managers the investigation becomes unwieldy. The heightened apprehen- siveness that led to such modifications, too, belonged rather to the period of inflamed controversy which is past, and for the more normal situation now prevailing the two-experimenter team will give assurance of adequate protection against error, even for the most crucial verification stage. The cautious reader may still fall back on confirmation for further guarantees. These four main requirements of conditions for a crucial in- vestigation in parapsychology have been outlined in a manner suited to the purpose of this book. Certain general practices of research tidiness could be added that apply to every research field. It is always wise, for instance, to draw up in advance a written plan for a conclusive research project. Special provision should be made at the start to meet all reasonably possible irregular con- tingencies (e.g., what to do with cocked dice in PK, or incomplete runs in ESP). Disposition of records, provision for duplicates, and a program of analyses can be provided to good advantage in the statement of design. There might be mentioned a great deal more on the side of good research habits. However, the scope and degree of emphasis followed will, we believe, adequately serve the needs and aims of most of those who wish to pursue inquiries in parapsychology with, of course, the exception of veteran workers in the field; these latter OBJECTIVE RESEARCH METHODS 39 should already have acquired the standards and the methods ap- propriate to the most careful stages of a psi investigation. Those who wish to acquire a reading acquaintance with the highest standards of controlled psi testing may, for example, consult the Pratt and Woodruff report.’ But it is well to keep in mind that every limiting condition on an experiment is a burden, and exces- sive use of precautions is unwarranted waste. The conditions should be calculated to fit the needs, as intelligently conceived. The conclusions, of course, depend upon the adequacy of the weakest feature, not upon an elaborate display of many precau- tions. V. Methods of Distinguishing Types of Psi Another level of methodology has developed in the research program in parapsychology to establish the different types of psi processes as distinguishable one from another.* For example, once telepathy and clairvoyance had been experimentally established, each under its own set of conditions, the question arose as to whether the two were, in the last analysis, experimentally distin- guishable. A similar question was raised about precognition and psychokineses. In each case, the evidence for any given type was sufficiently challenged by critical questioning to require new methods for what amounted to a re-establishment of the type concerned. A general account of these methodological distinctions will help in the appreciation of the quality of the research proce- dure on which the structure of parapsychology rests. Again, it was clairvoyance that first yielded to experimental attack and permitted a distinguishing line to be drawn around its phenomena. In clairvoyance tests designed to exclude the possi- bility of telepathy and precognitive telepathy, it was necessary to have the trials made in such a way that not only did no one know the card order during the test, but so that even when the checking * While this section is written from the point of view of the actual development of methods for distinguishing types of psi, the purpose is still one of presenting only a general description of methods. References to the literature will therefore not be given here, but they will be found in the later chapters in which the results of the research are discussed. 40 PARAPSYCHOLOGY was done no trace was left of the order in which the responses were made. Thus no one would ever know this order. In other words, the test scored the number of hits made but left no record of the order in which the calls or responses were made. Accordingly, precognitive telepathy was ruled out; no potential agent ever knew which target was for which trial when the final checking was done. This case against precognitive telepathy rests on the clairvoyance tests with matching methods, and depends on the assumption that the cards in a given pile that are laid down opposite a given key card are not identified in terms of their original positions in the pack. The issue could be investigated with somewhat better nicety by means of a clairvoyance test machine in which merely the total hits and trials are counted. To safeguard a telepathy test against the possibility of precogni- tive clairvoyance was more difficult. It was necessary to avoid having any card or other objective target recorded or existing any- where, either at the time of the test or later on. The agent or sender had to select the target mentally and, after the run was finished, to check the percipient’s record from his own subjective code. To serve the agent as a random guide in selecting the target order, a shuffled pack of numbered cards or a list of random num- bers might be followed; but the code which the agent used had to be one which he alone knew and which he could never record. No physical record could be allowed that could disclose the code, even by means of clairvoyance. The problem of introducing a second observer so as to make the test more reliable presented a greater difficulty. It was necessary for the agent to communicate his code to an assistant, using wholly subjective references in making his meaning clear. He had to convey his code by hints and vague clues to common memories, avoiding even an auditory stimulus that might serve as a basis for disclosure through clairvoyance. The procedure is exceedingly circuitous and perhaps not entirely logic-tight. Telepathy is the hardest of the psi types to isolate by distinctive experimental test. The test of precognition has been successfully safeguarded against the possibility of explanation by psychokinesis by a method of selecting the target order. This method involves an extremely complex computation, starting with the throwing of OBJECTIVE RESEARCH METHODS Al dice to get a set of numbers. These numbers are involved in a routinized but complicated operation with the use of an electrical computer, ending up with a set of numbers that, by means of a fixed code, indicates the targets of the test. Everything is me- chanical routine after the selection of the numbers by the throw of the dice. Although someone could, by means of PK, affect the fall of the dice that start the process of selecting the target series, he could not, in any conceivable way, produce a given set of targets by that means. The computation he would have to make to con- nect the dice with the end result would seem to be an impassable barrier. The psychokinesis test itself has been safeguarded against the alternative of precognition. The supposition of the counter- theory of precognition would be that the subject or experimenter, in selecting the face of the die which is to be the target for a given set of throws, might base his choice upon precognitive awareness of the way the dice were going to fall by chance in the series to follow. That is, he would choose the face he foresaw would turn up the most frequently. It is possible to eliminate this hypothesis by simply choosing the target face by the throw of a die (see p. 62). The routine adherence to the practice of always taking the target faces in the order from one to six would leave very little room for precognition, though there is a slight advantage in the other device mentioned. Other counter proposals have been made, including the use of the Latin Square method of determining random target sequence. This can be done to assure that the different faces will be equally represented in each subdivision of the data. If the simplest method of throwing a die to select a target is used, before the ex- periment is finished it is necessary to equalize the number of times each face is used as target. This requires only that the die be thrown again if a face is obtained after it has already been used as target the requisite number of times. The best evidence of PK, however, the internal decline effect known as “the quarter distri- bution” or QD result, is not affected by the precognition counter- hypotheses. The results had been originally collected for another purpose. (The QD analysis was a later research carried out by the Re-examination Method. ) 42 PARAPSYCHOLOGY For the most part the efforts that have been made to distinguish between the various types of psi have represented an advanced level of inquiry even for the research worker in parapsychology himself. Most of it has been done under the better controlled conditions appropriate to verification. We must remember, how- ever, that those not primarily concerned with the advancement of parapsychology proper will not be at this stage particularly con- cerned with these highly refined efforts at the discriminative in- vestigation of a specified type of psi phenomena. In other words, the investigator who wishes to use an ESP test in some related research area need not attempt to distinguish in a thoroughgoing fashion among clairvoyance, telepathy, and pre- cognition. For most purposes it would not make any great differ- ence which type of psi was involved. In any case, we do not know that the types represent fundamental differences. And if they do there is no evidence yet that one type substitutes for another which the subject is attempting to use. There is no reason to think, for example, that if a subject is attempting to succeed in a clairvoyance test that he does actually achieve his results by pre- cognitive telepathy even though the experimental conditions would allow such an alternative round-about way of response. This is not, however, to overlook the need for such clear-cut experimental distinctions as may be made. The methods presented in the sections of this chapter, along with the supporting techniques (Part IT) that implement them, are comparable in objectivity to the areas of science to which, in general, parapsychology belongs: first, psychology; and, more generally, biology. The specific techniques of investigation are naturally adapted to the phenomena to be dealt with and the con- ditions under which they must be studied. These were deter- mined by the spontaneous manifestations of psi capacity that initiated the research program in parapsychology; that is to say, they were largely determined by the nature of the phenomena themselves. The distinction between the exploratory and verification stages of research method has been strongly emphasized in this chapter in order to guide the student and research worker as quickly and OBJECTIVE RESEARCH METHODS 43 effectively as possible to the stage at which he should be working. It should be pointed out, however, that for the most part it is only the advanced investigator himself who is likely to be especially concerned with verification at its most rigorous level. If our inter- pretation of the need for this volume is correct, it is probable that most of those concerned with actual methods, those who will un- dertake psi testing in one interest or another, will deal mainly with what in this chapter have been ranked as exploratory procedures. Let it be made clear, then, that there is no ranking of these methodological stages such that one can say the more rigorously controlled the test method the better. It may, in fact, be the worse if the situation calls for a free-moving, more exploratory approach. For example, in the wide range of what might be called clinical applications of psi tests, ready adaptability in method is so important that the more elaborate procedures and precautions of a crucial experiment should not even be considered. Fortunately for parapsychology, however, some of those whose interest in psi begins as an incidental one may make first-rate discoveries that would call for further pursuit under the most advanced research design. Such an outcome is devoutly to be wished for and encouraged. If this general outline of the ways of investigating psi has been well enough presented to give an intro- ductory picture, the inquirer, on whatever front, will be able to find or develop the plan of procedure best suited to his purpose. The various adaptations of methods to particular uses such as clinical applications will doubtless develop many alterations; cer- tainly as the interest in psi expands into adjacent fields, the methods will have to be adapted to fit the specialized needs. It will be advantageous, however, to maintain the same basic stand- ards throughout and thus allow for easy comparison and interpre- tation of results across the boundary lines. The methods now in use will be found to adapt readily and widely without changing the basic structure. Reference 1. Pratt, J. G., and Wooprurr, J. L.: Size of stimulus symbols in ex- trasensory perception. J. Parapsychol., 3:121—-158, 1939. 44 PARAPSYCHOLOGY Additional Reading Ancter, R. P., Coss, P. W., DALLENBACH, K. M., Dunuap, K., Fern- BERGER, S. W., JoHNSON, H. M., and McComas, H. C.: Adequate ex- perimental testing of the hypothesis of “extrasensory perception” based on card-sorting. J. Parapsychol., 3:28-37, 1939. Burtt, E. A.: Principles and Problems of Right Thinking. New York, Harper, 1931. EprrortaL: Parapsychology and scientific recognition. J. Parapsychol., 16:225-232, 1952. EprrortaL: Rational acceptability of the case for psi. J. Parapsychol., 18:184-194, 1954. Eprror1aL: Some considerations of methods in parapsychology, J. Parapsychol., 18:69-81, 1954. Eprrortat: The value of reports of spontaneous psi experiences. J. Parapsychol., 12:231—235, 1948. Murpny, G.: The importance of spontaneous cases. J. Am. Soc. Psych. Res., 47:89-103, 1953. Porr, D. H., and Pratt, J. G.: The ESP controversy. J. Parapsychol., 6:174-189, 1942. Rue, J. B.: The Reach of the Mind. New York, Sloane, 1947, pp. 154-183. Rute, J. B.: Impatience with scientific method in parapsychology. J. Parapsychol., 11:283—295, 1947. Rung, J. B., et al.: Extrasensory Perception after Sixty Years. New York, Holt, 1940, pp. 22-69. Rune, J. B., Humpurey, B. M., and Pratt, J. G.: The PK effect: Spe- cial evidence from hit patterns. III. Quarter distributions of the half-set. J. Parapsychol., 9:150-168, 1945. Rue, L. E.: Conviction and associated conditions in spontaneous cases. J. Parapsychol., 15:164-191, 1951. Soa, S. G., and Pratt, J. G. ESP performance and target sequence. J. Parapsychol., 15:192—215, 1951. The ESP symposium at the A.P.A. J. Parapsychol., 2:247-272, 1938. Chapter 3 The Facts About Psi and Its Types , ¢ HILE we shall take for granted that the reader who has come so far as to begin this chapter will have a sufficiently open mind to consider this necessarily brief review of the case for psi, ade- quate references will be given for any who may wish more ex- tensive evidence. In presenting the facts about psi we must, of course, leave the reader to determine for himself the extent of his acceptance of them. At the same time, it is taken for granted that any accurate presentation of evidence on an important question merits atten- tion, whatever the preconceptions of the reader. Science—we all like to think—needs and accepts no authority; its course is deter- mined by its facts. The findings here summarized are receiving attention, however, not only because of the reliability of the evi- dence in support of them, but also because they are manifestly important to many departments of human interest. After a consideration of the evidence for the establishment of psi, there will be a review of the different types of psi occurrence that have been experimentally isolated. There will be left for succeeding chapters the facts about psi in its relation to the physi- cal world, about its psychological nature, and its relation to some of the other fields of science. I. The Evidence for Psi It is now safe to say—though only recently so—that the collec- tions of spontaneous case material themselves constitute valuable evidence in support of the occurrence of psi. It is quite true that this material would not be sufficient by itself, but along with the experimental evidence it offers a very considerable amount of 45 46 PARAPSYCHOLOGY support to the conclusiveness of the case. Now that the spon- taneous cases in the collections at different centers number in the thousands, and systematic classification and analysis of this mate- rial have been made by different workers, there emerges an im- pressive outline of the orderliness of the similar types of experience even though they come from widely different cultures and different periods of time. As research workers studying these reports ob- serve the recurrence of familiar patterns of experience, each with its identifying characteristics, the characteristics turn out to be as distinctive as is the clinical case material of the physician which characterizes types of disease syndromes.’ Accordingly, respect for this case material has grown as study has continued. It is a significant fact that each of the types of psi phenomena that have been observed and identified in the spontaneous case collections has now been demonstrated experimentally. Thus a mutual order of testimony from case study and experiment has resulted. But psi phenomena have been under investigation for at least 75 years, and experimental work now forms the main basis of evi- dence. The long exposure of the problems to controversy has itself led to a great deal of research as one explorer after another tried to improve on the work of his predecessors who had failed to win scientific recognition. Studies have cropped out in a number of adjacent fields in connection with other interests as, for instance, in the study of hypnosis, among psychoanalysts and other psy- chiatrists, among anthropologists, and in still other fields. Dur- ing the last 40 years there has been a growing interest in explora- tory testing of ESP in university laboratories, mainly in depart- ments of psychology. The great bulk of accumulated experi- mental evidence now available is a consequence of these scattered but numerous studies made either within the university laboratory or at least under the influence of standards set by the university researches. The first experiment which in our judgment met the criteria for a conclusive test of ESP was one that has come to be known as the Pearce-Pratt Series. This experiment, conducted at Duke Univer- sity in 1933-34,? was of the clairvoyance type with experimenter and subject in different buildings at least 100 yards apart. Dupli- cate records were kept both of the cards and of the subject’s re- THE FACTS ABOUT PSI AND ITS TYPES AT sponses, one copy of each being placed in an envelope and sealed immediately following the end of the session, and the sealed envelopes being delivered to a second experimenter. The results of the series were so far above chance expectation as to be highly significant and no alternative to ESP has ever been proposed (except the vaguely implied one that it could have been fraudu- lently produced ) that was not already anticipated and met by the experimental design. Since one phase of the experiment involved the presence of both experimenters throughout the session, con- spiracy would have needed to involve all three participants. The two experimenters in this case were the present authors. Through the succeeding years a number of other experiments followed in which the standards of control required for verification were maintained. Perhaps the most elaborately controlled of these was that published by Pratt and Woodruff* in 1939, about five years after the first publication of the Pearce-Pratt series. The Pratt-Woodruff series was likewise a clairvoyance experiment, and again it was conducted with the two-experimenter plan. The two experimenters operated throughout this series as checks upon each other to avoid the possibility of error in the production and recording of the results. A third member of the team played an essential part in the precautions, mainly to see that the record sheets were duly preserved and safeguarded by a system of inter- locking controls. In this experiment the subjects tested were 32 volunteers. Here, too, the scoring rate was highly significant and chance as well as all the other conceivable hypotheses were ruled out, leaving only the hypothesis of ESP. The confirmation of the case for ESP was not, however, at all confined to the Duke Laboratory. Other studies were made in other departments of psychology and elsewhere in this country as well as in Western Europe. By far the most elaborately controlled of these investigations were those conducted in London by Soal and Goldney* and later by Soal and Bateman. These were of the GESP (general extrasensory perception) type which call for more elaborate controls, but such were the safeguards introduced by Soal and his colleagues that these studies belong within the classification of conclusive tests. 48 PARAPSYCHOLOGY The ESP investigations by Soal and his colleagues offer evidence that is especially needed for those who are inclined to suspect that favorable ESP results may have been unduly affected by the experimenter’s belief in psi. (The suspicion is not consistent with the facts.) Soal was one of the more outspoken critics of the earlier ESP investigations when he began, and repeatedly during the course of a long period of searching for ESP subjects he an- nounced that his results were negative. It was months after his tests were completed that his attention was called to evidence of ESP in his data. This “indirect evidence” as we may call it, was, so to speak, forced upon his attention by another worker against his own anticipation. Soal had tested 160 subjects for ESP capac- ity and at first thought his results could be explained by chance. Another investigator, Whately Carington, meanwhile had found among his own ESP records a tendency on the part of subjects to “displace,” as he called it, and to hit the target which came before or that which came after the one set up for the subject at the time.* When he called Soal’s attention to this effect and asked him to examine his card-calling tests for displacement, Soal discovered that two of his own subjects had shown it.’ They had not gone above chance on the target, but on the “next door” targets they scored so strikingly that even when all the necessary corrections were made the results were still statistically significant. It was this displacement effect, then, that became the main basis of the further conclusive experiments under the direction of Soal and Goldney. Indirect evidence of various kinds was also turned up in other investigations, and all together it makes up a good part of the body of evidence of ESP. For example, in the early experiments there was evidence of a falling off of success in the runs or in the series of trials given as a block in the test situation. This decline in scoring seemed to be something of a characteristic of the test. At least it held for a considerable number of subjects in various in- vestigations. It was at first erroneously called a fatigue curve. Jephson,® who first gave primary attention to decline curves, pointed out that the pioneer study of ESP by Estabrooks® at Harvard had shown such a decline. Now Estabrooks himself did not base his conclusions upon this effect. But when this experi- THE FACTS ABOUT PSI AND ITS TYPES 49 ment was later evaluated for the significance of its decline in scoring rate in the run, this evidence alone gave it the status of an extrachance series.1° It was thus an incidental result unantici- pated by Estabrooks and even ignored in his estimate of signifi- cance. This unexpected finding in Estabrooks’ evidence would have a more telling effect upon some minds than would the obvi- ous direct results upon which he based his own conclusions. It might be well to turn to another branch of psi investigations for a third illustration of this indirect type of evidence. In the earlier work on psychokinesis, most of which would qualify only as exploratory by the standards of evidence presented in the pre- ceding chapter, final verification was based upon precisely this in- direct kind of proof. Although a number of experimenters had completed PK test series without suspecting that the data had any First Second Third First Second Third First Second Third run run run runs run” run run run run MECHANICALLY RELEASED HAND THROWN TOTAL Decline in scoring rate within the set of three runs in the first series of dice-throwing tests of PK (J. Parapsychol., 7:20-43, 1943). significance beyond that shown by the total scores, when later the records were analyzed more closely in the Parapsychology Laboratory internal declines in the scoring rate became manifest." These declines took the general direction that many ESP record sheets had shown—a falling off in scoring down the run; but there was also a falling off to the right as the record sheets were filled out. This gave, as a combined effect, the most pronounced de- cline between the upper left and the lower right quarters of the page. The analyses were carried out on records from a number of earlier PK research projects that had long been gathering dust 50 PARAPSYCHOLOGY in the files, and it was obviously an investigation of unanticipated results. But when, from the continuation of the study, confirma- tion emerged from one series of data to another so that finally a high order of significance was shown, the evidence of the operation of a PK function became overwhelming. It far surpassed the conclusiveness of the evidence from the general results themselves which had been anticipated by the separate investigators. In addition to the direct evidence of adequately safeguarded experiments and the supporting evidence of widespread indirect psi effects, there is a third type of support for the case for psi. This evidence emerges from studies of the relation of this capacity to other observable operations or conditions. One of the most familiar and best established of these lawful relations is shown by Schmeidler’? in her work on the association of ESP results with the subject’s attitude toward that capacity. The subject's attitude toward ESP was registered in advance of clairvoyance tests given to students in the classroom, and it was found that those with the more negative attitude (goats) tended to score at a lower rate than those taking a more positive attitude (sheep). The sheep- goat differences in scoring average were found to be fairly consist- ent over many experiments, and the results added up to a highly significant block of evidence. Without concerning ourselves for the moment with the nature of the relationship, the simple objec- tive fact that a long-continued and orderly association of scoring and attitude toward the test was shown is another indication of lawfulness. Other evidence based on psi’s relation to adjacent fields might be cited. For example, the recent ESP work of van Busschbach™® makes a similar point in a very different setting. Van Busschbach’s test of school children in the classroom has been carried out in three different general situations, in the cities of Amsterdam and Utrecht in Holland and in Durham and Burlington in North Caro- lina, U.S.A. Tests were designed for the fifth and sixth grades, but in Holland they were also given to pupils in the upper grades through high school. In Amsterdam only the fifth and sixth grades gave significant evidence of ESP and this held true as well when the experiment was repeated in Utrecht. Again in the U.S.A. only the fifth and sixth (of the four grades, fifth to eighth, tested ) THE FACTS ABOUT PSI AND ITS TYPES 51 scored significantly. There seems to be some lawful relation that holds over the area of testing involved, at least as far as this par- ticular experiment is concerned. Even at present when the psi function is little understood certain natural properties and con- sistencies become evident as the investigations proceed. There is still a fourth type of contribution to the kinds of evi- dence of psi. This is the evidence of rational acceptability which may be especially important to the mind that is not trained to the appreciation of scientific method itself. In order to be acceptable the findings have to be made reasonable. Most of the material to be presented in the chapters that follow concerns the relations of psi to other fields of science. Such interrelations make up the rationale of the newly discovered results. Familiarity with them will give such indications as we have gleaned as to how, and how well, psi fits into the scheme of nature as currently conceived. There are, however, some general points on this rational picture of psi that may be referred to now, especially since they are likely to be lost in the more specific treatments to follow. We have pointed out already that the experiments in parapsychology have confirmed in general what had already been suggested by the study of spontaneous cases. It is an important fact indeed that the experiments have followed and supported the main types of psi phenomena as exemplified in the experiences of everyday life. It is noteworthy, too, that as the types of capacity suggested by the spontaneous material took more definite form under experimental study, a certain pattern of orderliness within the whole field of phenomena began to emerge. We no longer had telepathy, clair- voyance, precognition, and psychokinesis as isolated phenomena. From their common qualities an essential unity could be recog- nized. All, for instance, occurred on a very elusive spontaneous basis, and even the best experimental efforts to regulate and con- trol any one of the four types have thus far failed to overcome this fugitive character. Certain general psychological characteristics were found throughout the whole range, and none was limited to one area of phenomena alone. Also, just as the spontaneous cases showed no apparent limitation of time and space, so those demon- strated experimentally likewise indicate a similar independence of physical relation. 52 PARAPSYCHOLOGY The result has been that, more than had been suspected in the early decades of parapsychology, the field of study was found to be concerned with some kind of systematic interaction (however unknown and nonphysical its nature). between the subject and the objective environment, a form of communication between the in- dividual and his surroundings. In ESP and PK then there has been discovered a system of reaction, one that parallels the sensori- motor exchange with which the individual most commonly inter- acts with his physical world. In fact, so systematic has the character of the psi function now been shown to be that it has been possible to infer the logical likelihood of a different type of phenomenon from the occurrence of one already verified. When, for instance, clairvoyance had been satisfactorly demonstrated, it was anticipated that psycho- kinesis should be found to occur also. The existence of a psi influence of the object upon the subject logically suggested that there should also be a reaction of the subject upon the object. The experiments in psychokinesis were introduced in this way. Likewise, from the fact that clairvoyance showed no consistent relation to space, it was inferred that it should similarly show no dependence upon time. This was the logic that led to the first precognition experiments as conducted at Duke in 1933. As the evidence of rational consistency in the expanding knowl- edge of psi phenomena grows with continued research, much of the earlier unacceptable strangeness disappears. It can now be said that a fully verified case for the occurrence of psi under the limitations specified in the reports has been made and all the criteria of scientific proof have been met. While an indefinite period of further investigation will have to follow before a suffi- cient understanding of psi can be reached to allow an effective grasp of its nature and an application of its principles, we at least know today that the phenomena occur, that the various types of effects can be identified, and that a complex system of related find- ings have emerged. We turn now to examine the evidence which differentiates these various types of psi phenomena. In doing so one change of per- spective will be adopted that needs to be specified here. As we pointed out in the chapter on method, there is a great deal of THE FACTS ABOUT PSI AND ITS TYPES 53 difference in the standards of evidence required for the establish- ment of a revolutionary new finding and for the elaboration of subordinate details regarding the nature of the new phenomenon. For the establishment of psi only the highest standards of evidence —higher than those ordinarily familiar in science—could be ac- cepted as adequate to overcome the special skepticism en- countered. But in turning attention to the distinction between types of psi phenomena we shall occasionally consider blocks of evidence that, in the establishment of the case for psi itself, would have been rated only as of good exploratory quality. For ex- ample, a two-experimenter plan may not always have been in use in the evidence considered in the rest of the chapter, although for the most part it was. II. The Case for Clairvoyance As should have been expected from the simplicity of the experi- mental controls required, clairvoyance experiments are the easiest of all to conduct. As a result a great many more trials have been made in testing for clairvoyance than for other types of psi phenomena. Not only is it easier to control against the more com- mon experimental errors such as possible sensory cues or decep- tion by the subject, but it is also easier to eliminate any alternative hypothesis (i.e., of another type of psi) that might be applied to the data. To rule out ordinary telepathy as familiarly conceived, it is necessary only to keep the pack of target cards inverted throughout the shuffling and testing procedure. When eventually the cards are looked at for recording, the percipient has already recorded his responses and telepathy from the experimenter is impossible. But after the establishment of what was at least a preliminary case for precognition, a counterhypothesis was pro- posed to the effect that the results of clairvoyance tests could be explained by a combination of precognition and telepathy. The percipient, instead of using clairvoyance, could look forward to the point at which the cards were recorded by the experimenter and by precognitive telepathy acquire information of the card order from him. 54 PARAPSYCHOLOGY As soon as this alternative of precognitive telepathy was pointed out as a defect in the case for clairvoyance, the proposal was made that clairvoyance be tested with a machine that would record only the total number of trials and the total number of successes. This would eliminate the possibility of precognitive telepathy. Results giving significant evidence of clairvoyance were reported by Tyrrell,* who used such an apparatus in an exploratory series of experiments. The point was met, too, in another way. This was done by card-matching techniques as in the Humphrey and Pratt “chute” series.1* In this a pack of twenty-five cards were distributed by the subject who dropped each card through an opening marked by one of the five key cards: The cards fell in five disarranged piles and the order in which they were laid down was not noticed or recorded. The experimenters, in picking up each pile for recording and checking, paid no attention to the order. Accordingly, the subject, even if he had been inclined to try precognitive telepathy, would not have had an ordered se- quence of card observations which he might observe by precogni- tion as the experimenter made his record of the cards. Even if the subject were to try to think (unconsciously ) as he indicated where the first card was to be placed, “What will the experimenter find this card to be when he picks it up and looks at it?” It appears doubtful that he could foresee (by precognitive telepathy) what the card was going to be in a certain place and time and still be free to put it there. In any event, it would be impossible unless the experimenter were consciously or unconsciously keeping track of the cards as he looked at them. At least for the present the results from a number of the well-controlled matching series of clairvoyance tests have sufficiently satisfied the critical mind so as not to have made it seem urgent to develop a new clairvoyance test machine just to carry the matter to a further point of deter- mination.” The case for the experimental demonstration of clair- voyance appears to be sufficiently clear-cut for the present re- quirements of the field. III. The Problem of Telepathy Telepathy is by far the most familiar of the different types of psi phenomena. Most of the spontaneous cases reported are open to THE FACTS ABOUT PSI AND ITS TYPES 55 interpretation in terms of either telepathy or clairvoyance, but as should be expected, most people having such experiences think of them as telepathic. The exchange between people is the most needed, the most interesting, and the most dramatic type of extra- sensory communication. Also, there is, in certain cultures, a philosophical inclination to regard telepathy with more favor than clairvoyance. But even though telepathy is both more popular, more familiar, and more readily acceptable even to the general scientist, it has proved to be a much more difficult phenomenon to investigate and experimentally isolate from clairvoyance. Until the refinement of methods introduced at the Duke Labora- tory in the early thirties, there had not even been any attempt to conduct telepathy tests in a way that excluded the possibility of clairvoyance. The agent always had an object or objective record which theoretically could have served as the target just as easily as the agent's thought. The first efforts at separation of clairvoy- ance and telepathy aimed only at excluding the possibility of con- temporaneous clairvoyance, merely requiring that the agent have no object or objective record at the time the percipient was at- tempting to apprehend his thought.’* With the signal that the subject’s choice had been made, the agent was free to make his own record. But here again (as had occurred to the case for clairvoyance) the introduction of the evidence of precognition brought in a new angle of consideration.” Precognitive clairvoy- ance, then, had to be considered as a counterhypothesis, and this gave more difficulty than had the exclusion of simple clairvoyance. As a provision against precognitive clairvoyance it was required that the agent make no permanent record at all of the sequence of symbols which served as the targets for the pure telepathy test. To select the symbol sequence he could use a deck of number cards and a code which he himself had mentally devised but had not recorded (or expressed in any physical way). He could go through the test much the same as he had done in the first efforts at a pure telepathy test, with the exception that no record ever was made of individual targets. Only the record of the total run scores was recorded. This procedure was adequate for an exploratory test but not for a conclusive one because of the need for a second experimenter 56 PARAPSYCHOLOGY or an assistant to verify the agent’s checking of the percipient’s record. To get around the difficulty and obtain a second check it was necessary that the agent somehow transfer his code to another person without leaving any objective trace that could make the secret available to the percipient by clairvoyance. This step was achieved by using a veiled method of communica- tion that depended for its meaning upon common memories of the two persons concerned. No one else, even if he heard them, would have known what the two meant in their conversation which transferred the code unless telepathically he knew what the two persons were thinking and what their common memories had been. By this method experiments in pure telepathy were carried out with positive results by McMahan at Duke” and then by Soal in London.* Accordingly, the question of telepathy has, up to this stage of clarification, been answered in the affirmative. One person can apprehend another person’s thought without the use of intermediate objective records. Whether this communica- tion is from one mind to another, without a direct involvement of nervous systems which would introduce something else than direct thought transference, cannot be decided at the present stage of our knowledge of the human organism and personality. Is is not in- conceivable that some clairvoyant impression of the agent’s ner- vous system, vocal cords, or other physical accompaniment of thought may be playing a part in the so-called pure telepathy tests. It is better to say that as far as present knowledge of mind-brain relation permits an experiment to be designed on the matter, telepathy has been demonstrated between one person and another. That is where the matter will have to be left for the present. IV. The Case for Precognition There were two distinct grounds for inferring the occurrence of precognition in advance of any experiment to test the hy- pothesis. First, there had been the evidence of spontaneous cases. Throughout history and in all the case collections examples of apparent prophecy or precognition were common. When, a few years ago, L. E. Rhine’ classified the Duke collection with respect * Reference 5, pp. 255-258. THE FACTS ABOUT PSI AND ITS TYPES 57 to precognition, it was found that at least 40% of the cases in- dicated ESP of future happenings. There was, moreover, no ap- parent difference in the character of these experiences other than in the fact that the event, instead of being only remote in space, was also in the future. While this spontaneous material was not regarded as offering conclusive evidence, it was noteworthy that precognition cases often made a stronger impression than instances of contemporaneous ESP. The timing of the experience in ad- vance of the event with which it was connected, while it allowed greater range for coincidence, also gave more opportunity for the communication of it and in some cases the recording, as, for ex- ample, in letters. The second basis which made precognition predictable was in the experimental findings on ESP. By December, 1933, when pre- cognition was first subjected to experimental test at the Duke Laboratory, a considerable amount of exploratory evidence had accumulated to indicate that ESP showed no regular relations to distance between subject and object. This experimental confirma- tion of the impression already given by the spontaneous case material that distance was no limiting factor in ESP led to the inference that the ability should not be expected to be related to time either. In a time-space system independence of space would have to mean comparable freedom from time. It was accordingly anticipated that subjects would be able to predict the order of cards prior to the shuffling. The experimental study of precognition has gone on in a limited way for more than 20 years; it is still an active field of inquiry and may prove to be the most stimulating branch of psi research for a long time to come. The first experiments involved the at- tempt to predict card orders in advance of hand shuffling of the pack. When this had been found to succeed, mechanical shuffling was then introduced to get around the possibility that hand shuf- fling might be influenced by ESP itself.” Later still it was con- ceded as a theoretical possibility that the card shuffling by ma- chine could be influenced by PK and thus make the resulting card order conform to the predictions already registered. As a third advance, then, there came the introduction of what is known as the “weather cut.”*"’ Figures printed in temperature readings 58 PARAPSYCHOLOGY published in the daily press were by specified rules taken and used as the basis for the cut to be made in the packs of cards used as targets. This introduced a large order of natural phenomena as an essential link—something presumed to be beyond the control of PK. The test procedure as a whole represented a complex system in itself so that the alternative of matching calls against future tar- gets in some other way than by precognition would involve much more than exerting an influence on the weather or the thermom- eter. In fact, the alternative hypothesis is rather fantastic. Sig- nificant results were obtained under conditions using the weather cut and the two-experimenter plan. In the Rhine and Humphrey investigation of this problem two series were carried out, each in- dependent of the other, with results which, while only marginally significant, supported each other. A very considerable amount of earlier work had been done, some on the two-experimenter level, both at the Duke Labora- tory**”° and in England (by Tyrrell,** Carington,® and Soal and Goldney*) all of which involve precognition; but alternative ex- planations do remain as theoretical possibilities in these experi- ments. There is no need to go over these exploratory studies in detail here. In recent years improvements of design have been introduced to give still further assurance that any significant results obtained can be attributed only to a precognitive type of psi. A number of studies in the exploratory category have been carried through at the Duke Laboratory under these improved conditions.7*>** The results are sufficient to encourage their continued use and sufficient to keep this challenging branch of study active. The essential advance in these studies is that the final step in the selection of the targets is a complicated calculation, done by means of an elec- trical computing machine. This calculation is beyond anything the human mind would be capable of doing. The routine is rigidly fixed, but of course comes up with a different set of num- bers each time—numbers that in no conceivable way could have been forced to come out as they did and could only have been! foreseen by true precognition. Data of a higher order of significance than is ordinarily required may reasonably be desired for a conclusion that will have such THE FACTS ABOUT PSI AND ITS TYPES 59 revolutionary consequences as the establishment of precognition. Most of the parapsychology workers who followed the ESP re- searches and advanced through the different stages of designing precognition experiments were satisfied at the stage of the “weather cut” method of target randomization. Some at even still earlier stages thought the evidence conclusive. To those, how- ever, to whom precognition is philosophically impossible all the evidence will still probably not be sufficient. For those who con- sider that the experimental work was only needed to confirm the rational expectations we have mentioned, the demands for verifica- tion have already been sufficiently met. But if the present strong indications are correct, the accumulation of evidence will go on until opposing philosophies give way, as they eventually must do under pressure from reliable experimental results. V. The Case for Psychokinesis The approach to psychokinesis was very similar to that leading up to the experimental study of precognition. There had, in the reports of spontaneous “psychic” experiences, been numerous in- stances in which some unexplainable physical effect was reported —the stopping of clocks, falling of pictures, and the like, generally associated with a crisis or tragedy involving a member of the family. The interpretation usually given by those to whom these physical effects were manifested was that some personal agency brought them about in a way that no known physical principle could account for. There was implied some direct action of mind over matter as the term psychokinesis denotes. It would have been, however, quite as reasonable to expect some such effect as PK from a rational interpretation of ESP. Be- ginning with the analogy of the sensorimotor interaction between the subject and his environment in its more familiar manifestation, and having found in extrasensory perception the counterpart of sensory perception, it seemed reasonable to look for evidence of an extramotor response to pair off with the familiar motor response system. Or again, (using one of the familiar patterns of thought followed in all the sciences, the law of reaction) when it was established that an object can be cognized by means of ESP it 60 PARAPSYCHOLOGY seemed to follow logically that a reaction to the action should be expected to occur likewise. In other words, when an object and subject were found to interact in one direction it was anticipated there would also be an effect in the reverse direction—from the subject to the object. Accordingly at a certain stage of experimen- tal development of the ESP work it seemed justifiable to look for _ PK experimentally. Historically there had been many ineffectual efforts made to in- vestigate claims of physical effects said to have been produced by extraphysical influences or agencies. However, the first investiga- tion of PK by methods that lent themselves to adequate control began with the adaptation of dice-throwing as a laboratory test at Duke early in 1934.” After nine years of exploratory experiments the Duke Laboratory arrived at a definitive approach to the prob- lem which meets the requirements for verification on its more ad- vanced level. These conclusive studies (made, incidentally by the Re-examination Method) were made on the records of eighteen separate investigations carried out in, or in conjunction with, the Duke Laboratory. The individual investigations were, for the most part, different, but all of them involved the same essential operation, the subject’s conscious effort to influence the fall of dice so as to make a specified face or combination of faces turn up. It had been observed in re-examining certain PK test data that there was a tendency for the scoring to decline to the right and downward on the page as the tests proceeded. Consequently an analysis was done to check up on both of these decline tendencies in all the PK series that had been recorded in such a way that the record sheets could be divided into quarters. Then the upper left and lower right quarters were compared as the ones which were expected to show the greatest difference in scoring rates. This diagonal decline became a mark and measure of PK evidence. In the first report by Rhine and Humphrey” the quarter distribution or QD of the eighteen series was given as one composite value. The evidence was highly significant of a reliable trend which could not conceivably be attributed to any other factor than a mental one having to do with the direct influencing of the dice. A later study was made that was in every respect independently confirma- tory. It was based upon eight of the eighteen series in which eS © \ WY ae za | A on! ‘ Ke 62 PARAPSYCHOLOGY smaller units of recording were used, units called half-sets.*® These were also given the QD analysis and the composite diagonal decline obtained showed once again an extraordinarily high order of statistical significance. In a subsequent report the inde- pendent analysis of the same material by Pratt** exemplified the fact that the case now has the special advantage that the entire analytic study is repeatable by any qualified examiner. But there is the rather hair-splitting argument that perhaps the subjects in their PK performance may be exercising precognition of the way the dice are going to fall by chance, especially since the procedure in a number of the experimental series allowed the sub- jects to choose for a given session (or set or other unit) whichever one of the possible targets he preferred for that occasion. Perhaps, the argument ran, the subject (or the experimenter) precognized the whole series and made some mental appraisal (unconsciously, of course) as to which target face would give him the highest scores for a given session or set. Probably nothing can give the reader a better idea of the ex- tremes which the demands for acceptable experimental design reach in parapsychology than this use of precognition as a coun- ter-hypothesis to PK. Yet it is only a little, if any, less reasonable than the extremes to which PK has been urged as a counterhypoth- esis bearing on the evidence for precognition. All these alterna- tive explanations need to be ruled out in this field of research, whether or not they may involve a good counter claim. The main hypothesis under test is itself new and debatable, and counter- hypotheses need not have much justification in order to demand full consideration. At any rate, it is possible to rule out precognition as a counter- hypothesis to PK. To do so it is necessary only to agree upon a rigid order of target face and to adhere to it throughout the series of tests. This was done in more than one investigation.**** Better still, as sometimes happened, the subject was allowed to determine his own target for a given unit by throwing a die. Then, if pre- cognition entered into it, it would have to be through the PK in- fluence on this die.** At least one investigation has been made with the use of an elaborate design (Latin Square method) of selecting the target sequence by which is excluded the step-by- THE FACTS ABOUT PSI AND ITS TYPES 63 step choice of target on which the counterhypothesis depends.** But the best answer to the precognition counterhypothesis is given by the QD analyses already described. It adds something too that these were made on the data long after the tests were finished. These give the best evidence of PK, and they show that the hits were not a selected chance distribution as the precognition coun- terhypothesis assumes. In general it can be said that a good case has been made for the occurrence of PK as an aspect of psi. It is the newest of the dis- tinguishable psi phenomena and as a result much of the research has been concentrated in the Duke Laboratory, just as it has with precognition. Among the important independent confirmations that have, however, been carried out in other centers of research is that by McConnell, Snowden, and Powell of the University of Pittsburgh, in which a completely mechanized operation was in- volved, including the photographic recording of the fall of the dice.* References 1. Reme, L. E.: Frequency of types of experience in spontaneous precognition. J. Parapsychol., 18:93-123, 1954. 2. Rue, J. B., and Pratt, J. G.: A review of the Pearce-Pratt dis- tance series of ESP tests. J. Parapsychol., 18:165-177, 1954. 3. Pratt, J. G., and Wooprurr, J. L.: Size of stimulus symbols in extrasensory perception. J. Parapsychol., 3:121—158, 1939. 4. Soat, S. G., and Gotpnry, K. M.: Experiments in precognitive telepathy. Proc. Soc. Psychical Res., 47:21—-150, 1943. 5. Soat, S. G., and Bateman, F.: Modern Experiments in Telepathy. New Haven, Yale, 1954. 6. Carnmncton, W.: Experiments on the paranormal cognition of drawings. Proc. Soc. Psychical Res., 46:34-151, 1940. Published simultaneously in J. Parapsychol., 4:1—134, 1940. 7. Soa, S. G.: Fresh light on card guessing—some new effects. Proc. Soc. Psychical Res., 46:152-198, 1940. 8. JEPHsoN, I: Evidence for clairvoyance in card-guessing. Proc. Soc. Psychical Res., 38:223—268, 1929. 9. Estaprooxs, G. H.: A contribution to experimental telepathy. Bull. Boston Soc. Psychic Res., Bulletin V, 1927. 21. 22. ne sr 27. 28. PARAPSYCHOLOGY . Reg, J. B.: The Reach of the Mind. New York, Sloane, 1947, p. 170. . Ruwe, J. B., and Humpurey, B. M.: The PK effect: Special evi- dence from hit patterns. I. Quarter distributions of the page. J. Parapsychol., 8:18-60, 1944. . SCHMEDLER, G. R., and Murpny, G.: The influence of belief and disbelief in ESP upon ESP scoring level. J. Exper. Psychol., 36:271-276, 1946. . Van Busscupacu, J. G.: An investigation of ESP between teacher and pupils in American schools. J. Parapsychol., 20:71—80, 1956. . Carincton, W.: Telepathy: An Outline of Its Facts, Theory, and Implications. London, Methuen, 1945, pp. 91-92. . TyRRELL, G. N. M.: The Tyrrell apparatus for testing extrasensory perception. J. Parapsychol., 2:107—118, 1938. . Humpsney, B. M., and Pratt, J. G.: A comparison of five ESP test procedures. J. Parapsychol., 5:267—292, 1941. . Rene, J. B.: Telepathy and clairvoyance reconsidered. J. Para- psychol., 9:176—193, 1945. . Rewe, J. B.: Extrasensory Perception. Boston, Bruce Humphries, 1934. . McMauan, E. A.: An experiment in pure telepathy. J. Parapsy- chol., 10:224—242, 1946. . Rue, J. B.: Experiments bearing upon the precognition hypoth- esis. III. Mechanically selected cards. J. Parapsychol., 5:1-57, 1941, Rue, J. B.: Evidence of precognition in the covariation of salience ratios. J. Parapsychol., 6:111—-143, 1942. Rue, J. B., and Humeurey, B. M.: A confirmatory study of sali- ence in precognition tests. J. Parapsychol., 6:190—219, 1942. . Hutcuison, L.: Variations of time intervals in pre-shuffle card- calling. J. Parapsychol., 4:249-270, 1940. . TyrreLL, G. N. M.: Further experiments in extrasensory percep- tion. Proc. Soc. Psychical Res., 44:99-168, 1936. . Manean, G. L.: Evidence of displacement in a precognition test. J. Parapsychol., 19:35-44, 1955. . Osis, K.: Precognition over time intervals of one to thirty-three days. J. Parapsychol., 19:82-91, 1955. NiELsEN, W.: An exploratory precognition experiment. J. Parapsy- chol., 20:33-39, 1956. NiELsEN, W.: Metal states associated with success in precognition. J. Parapsychol., 20:96—-109, 1956. THE FACTS ABOUT PSI AND ITS TYPES 65 29. Rute, J. B., and Rute, L. E.: The psychokinetic effect: I. The first experiment. J. Parapsychol., 7:20-43, 1943. 30. Rue, J. B., Humpnurey, B. M., and Pratt, J. G.: The PK effect: Special evidence from hit patterns. III. Quarter distributions of the half-set. J. Parapsychol., 9:150-168, 1945. 31. Pratt, J. G.: A reinvestigation of the quarter distribution of the (PK) page. J. Parapsychol., 8:61-63, 1944. 32. Pratt, J. G., and Wooprurr, J. L.: An exploratory investigation of PK position effects. J. Parapsychol., 10:197—207, 1946. 33. Date, L. A.: The psychokinetic effect: The first A.S.P.R. experi- ment. J. Am. Soc. Psychical Res., 40:123-151, 1946. 34. Humepurey, B. H.: Simultaneous high and low aim in PK tests. J. Parapsychol., 11:160—174, 1947. 35. THoutess, R.H.: A report on an experiment on psychokinesis with dice, and a discussion of psychological factors favouring success. Proc. Soc. Psychical Res., 49:107—130, 1949-1952. 36. McConnett, R. A., SNowDEN, R. J., and Powe 1, K. F.: Wishing with dice. J. Exper. Psychol., 50:269-275, 1955. Additional Reading A digest and discussion of some comments on: Telepathy and Clair- voyance Reconsidered. J. Parapsychol., 10:36—-50, 1946. Birce, W. R.: A new method and an experiment in pure telepathy. J. Parapsychol., 12:273—288, 1948. Mounobte, C. W. K.: The experimental evidence for PK and precogni- tion. Proc. Soc. Psychical Res., 49:61—78, 1949-52. Mureny, G.: Needed: Instruments for differentiating between telep- athy and clairvoyance. J. Am. Soc. Psych. Res., 42:47-49, 1948. Nasu, C. B.: Psychokinesis reconsidered. J. Amer. Soc. Psychical Res., 45:62-68, 1951. Rung, J. B.: Precognition reconsidered. J. Parapsychol., 9:264-277, 1945. Reve, J. B.: The psychokinetic effect: A review. J. Parapsychol., 10:5—20, 1946. ScHMEIDLER, G.: Position effects as psychological phenomena. J. Parapsychol., 8:110-123, 1944. Chapter 4 Psi and the Physical World I. First the Facts F OR THE last two decades it has been possible to define the field of parapsychology in a clear-cut fashion as one that deals with | phenomena not explainable by physical principles. There is a great part of mental life that may or may not be nonphysical, but parapsychology at the present stage is not concerned with effects for which the interpretation is ambiguous. In order to be con- sidered as parapsychological the phenomena must be demonstra- bly nonphysical. That is, they must occur under conditions that clearly eliminate the types of operation known as physical. In their spontaneous occurrence the phenomena of parapsychology appear to defy physical explanation and when examined experi- mentally they can be proved to be beyond the reach of physical explanation. (We need hardly add that we are using terms and concepts in their current meanings; any other would be too con- jectural for scientific use. ) It is a matter of history that the founding of this branch of sci- ence derived its initiative from the interest many scholars of the nineteenth century felt in discovering whether all nature was, as was assumed in the growing philosophy of materialism, a purely physical system. Are there mental processes that are not a part of the world of physics? In their search for an answer to this question the founders of parapsychology were looking for possible nonphysical phenomena in nature that might be scientifically ob- served and described. A. Distance and ESP To these early explorers reports of spontaneous thought-trans- ference occurring between individuals separated by great dis- 66 PSI AND THE PHYSICAL WORLD 67 tances made the strongest appeal of all the current psychic claims. The apparent meeting of mind with mind in spite of intervening physical barriers would, if it could be reliably established as a natural phenomenon, argue strongly against a wholly physicalistic interpretation of human personality. The first step undertaken, that of collecting accounts of such spontaneous happenings (which came to be called telepathy) not only deepened the impression among scholars that a valid principle was operating in such cases; it strengthened the suggestion that this operation was completely independent of any known physical condition. It seemed to make no difference whether the percipient and the agent were separated by short distances or by very long ones, so far as either the frequency or the vividness of the experiences was concerned. When, after some decades of introductory inquiries, better con- trolled and more systematic investigations were undertaken, the distances that were introduced, often incidentally, did not seem to affect the results in any regular way. In some experiments there were higher rates of success at the shorter and in others at the longer distances. When the Pearce-Pratt series of ESP tests introduced a com- parison of distances in the Duke experiments, the scoring rate for the long distance tests (involving distances of 100 and of 250 yards) was about 30 per cent when chance expectancy was 20 per cent. Earlier work by the same subject (with the cards within arm’s length) had averaged approximately 32 per cent in com- parably large series of runs. In the Pearce-Pratt series at 100 yards his scoring rose for the first experiment consisting of 300 trials to an average of 40 per cent, but a careful study indicates that there were important psychological differences in the timing and the preparation for this series that gave it precedence over the earlier short-distance work. When later on at a distance of 250 yards he scored only 27 per cent, it was very evident in the scoring irregularities that psychological factors were again in- fluencing the rate of success.