Hypnosis

Theory, Research and Application

Irving Kirsch, Michael Heap, Michael Heap

• Publisher: Routledge
• Year: 2017
• ISBN:
  9781351929295
• Edition: 1
• Topic: Psychology
• Subtopic: Hypnotism
• Index: Psychology

Modern hypnosis can be traced back to the 18th century and during this period mesmerism, as it was then known, was a healing practice which spread throughout Europe and North America. Since then hypnosis has been treated primarily as a psychological phenomenon and theories about hypnosis are grounded in mainstream psychology and its related disciplines. Most recently it has been subject to extensive clinical trials to investigate its therapeutic effectiveness. In their comprehensive introduction to this invaluable collection the editors trace the historical development of hypnosis, providing an excellent review of the theories that have tried to explain how hypnosis works and reflecting on the cultural and scientific attitudes and practices that prevailed at various times. They have selected the most important previously published papers that reveal how a scientific approach to understanding hypnosis as a psychological phenomenon has emerged over the last 70 years. They have also included a selection of reports on clinical applications and on legal and forensic issues. As such this volume will prove an invaluable reference resource for researchers and students already in the field and new scholars interested in learning more about hypnosis.

Part I

The Birth of Modern Hypnosis

[1]

QUANTITATIVE METHODS OF INVESTIGATING HYPNOTIC SUGGESTION^1*

PART I

BY CLARK L. HULL

YALE UNIVERSITY

IN the preface to the fourth edition of his well known work on hypnosis² Moll expresses the opinion that little or nothing remains to be discovered in the field of hypnotic phenomena (Symptomatology). He says: “Very little has been added to our knowledge of these questions during the last few years, and it would appear that this branch of hypnotic research is fairly exhausted, though of course, it may one day happen that it will have to go through a searching revision which will prove instructive.”³ The history of science shows that similar views have been put forward from time to time in the various fields of scientific research, always to be disproven by subsequent events. Moll’s pessimistic prediction most certainly will be no exception. It is one of the purposes of the present article to show that the possibilities of research in hypnotism not only are not exhausted but that, comparatively speaking, they have as yet scarcely been touched.

Perhaps the most effective way of establishing such a thesis as that just put forward, is to demonstrate the possibilities of fruitful research by concretely pointing them out. This it is proposed to do to the extent of outlining over a hundred typical experimental projects from this rich field.⁴ It is hoped that this concrete exhibition, at once of our ignorance regarding the major hypnotic phenomena and of its remedy, will ultimately bring about an increasing number of exact and carefully controlled scientific investigations of hypnotism.

It is scarcely an exaggeration to say that the present state of hypnotic knowledge is a scientific scandal. It will be recalled that Mesmer was a contemporary of Benjamin Franklin. During the period of something over a century and a half since Franklin’s kite experiment (1752), electricity has developed into one of the most exact and quantitative sciences in existence. After approximately the same period (Mesmer propounded to the scientific world his views on animal magnetism in 1775), we find hypnotism for the most part still languishing in the hands of charlatans and mystery mongers. Except for a little notable work performed during the last decade, scarcely anything of scientific significance has been done for a century. During this period almost nothing has been accomplished save the more or less imperfect correction of experimental blunders committed by earlier workers.

It is not as if this remarkable backwardness in the development of hypnotism as a science had been due to lack of attention. Actually throughout this long period there has been continuous and widespread experimental activity in this field. The meager scientific results from all this really immense expenditure of human energy has resulted to a considerable extent from the workers wasting their time in mere dabbling. For the most part they contented themselves with repeating the classical experiments: inducing the trance, producing catalepsies, analgesias, post-hypnotic amnesias, and acts by post-hypnotic suggestion, but without significant variation from the procedures employed thousands of times before by previous experimenters. To a large extent this is true even today. There are signs, however, that this long period of sterility is rapidly drawing to a close. It is the hope of the author that the following suggestions of experimental procedures will aid in hastening the renaissance in hypnotic research which seems to be on its way.

OUTLINES OF EXPEBIMEETAL PROJECTS AND PROCEDURES⁵

1. It is obvious to all who have had any experience in putting people into the hypnotic trance, that some persons are far more susceptible than others. Indeed, occasional individuals appear to be quite uninfluenced by the hypnotic technique. This last is particularly paradoxical since most psychological processes, such as the ability to perform the various types of learning, are found to some, though varying, degree in all normal individuals. Moreover, it is known that the quantitative distribution of most human abilities is strictly continuous, approaching the normal or Gaussian form. In this connection it becomes a matter of some interest to know the form of the distribution of susceptibility to the trance, particularly at that point of the scale where the minimal positive response passes over—apparently—into complete failure to respond.

For this problem to be solved in a satisfactory manner, a large homogeneous group of psychologically naive subjects is needed. To secure a measure of susceptibility to the trance each subject should be subjected to a standard trance procedure by a single experimenter, lasting say twenty minutes. The measure of individual susceptibility should be the time required to induce a given standard of response. Of the various hypnotic phenomena available as a criterion for this purpose, probably the final closure of the lids is the best, because (1) lid closure is one of the most generally obtainable responses and (2) it can be observed and recorded most readily. The subject should be instructed very definitely not to close his lids voluntarily but only as the result of the suggestion.

The time required to induce final closure could be taken with the aid of a good stop-watch. Since the lids frequently close for a few seconds at a time before final closure takes place, a watch with a double stop attachment should be used, the one hand being stopped at each apparent closure and released again every time the lids open. The reading at the stop marking the final closure would then be the time required. In case it were desired to secure a record of the various temporary closures, this could be secured readily by using a kymograph provided with a time marker and a magnetic signal marker, the latter connected with a battery and a key. An assistant could watch the subject’s eyes and press on the key during the period of each closure. The smoked-paper record would then show the detailed history of the closures.

A dot distribution could be constructed from the time scores made by the subject, each subject being represented by a dot. These results could then be subjected to various forms of statistical treatment to determine whether the subjects giving positive responses taken alone constitute a “normal” group, or whether the individuals showing no response are required in order to complete the “slow” end of the presumably Gaussian distribution surface, and so on.

2. The differences in susceptibility to the trance noted under project No. 1 raise various questions: Are the differences in trance susceptibility due to an inherited organic positive or negative suggestibility! Or are they expressions of a more or less specialized set of socially conditioned habits? Are they due to differences in the personalities of the subjects? Are they significantly related to other aspects of the subjects’ behavior, particularly such as may be sampled by psychological tests ? The degree of correlation between trance susceptibility and various test scores should have considerable significance as to the essential nature of the particular process taken as the criterion of the trance.

Among the tests which it might be well to try for this purpose are one or two of the better verbal “intelligence” tests, the Kent-Eosanoff association test, an introversion-extroversion test and a considerable variety of tests presumably depending upon waking suggestibility and ideo-motor action, the stimulus of the latter being understood as originating outside the subject’s organism. Some of these are: the tendency to move imitatively when watching some one making strong muscular effort; the tendency when the subject is standing with the eyes closed to sway forward when given quiet but continuous suggestions that he is doing so; the tendency, when holding a small bob suspended by a thread, to gradually make it swing in a direction indirectly suggested; the inability to unclasp the hands, to bend the arm, or to take the foot from the floor when told emphatically that it can not be done.

The classification of trance susceptibility in this case might be based on the number of subjects from a group like that of project No. 1, who report respectively (1) complete amnesia, (2) partial amnesia, and (3) no apparent amnesia, at the end of the standard 20-minute trance procedure. With this classification there might be computed either the bi-serial r, the tetraehoric correlation coefficient, or the coefficient by the four-fold-table method. If, on the other hand, the criterion of lid closure as described under project No. 1 should be employed, the ordinary Pearson correlation coefficient could be utilized.

3. If a criterion of trance susceptibility were used in project No. 2 which would permit of the computing of the Pearson correlation coefficient, the results from that investigation would make it possible to organize a test battery for estimating susceptibility to the trance, the several tests of which could be accurately weighted by a multiple regression equation. The criterion as described under project No. 2 would also permit of the organization of a battery but its weighting would be very rough and crude. Such batteries as these, especially if the hypnotic score itself were included, might also be very useful in forecasting numerous vocational aptitudes involving suggestibility. It is possible that this trait or combination of traits is much more significant in various occupations, especially those primarily dealing with people, than is generally realized.

4. Pierre Janet has suggested that hypnotics are especially susceptible to fatigue. It would be an easy matter to test the truth of this assertion by testing on the ergograph a group of subjects like that suggested in projects No. 1 or No. 2 and then correlating the fatigability as shown by the ergograph with the degree of trance susceptibility. Appropriate corrections would, of course, need to be made to render comparable the rate of fatigue for people of different muscular equipment.

5. There is some reason to believe that individuals in an advanced state of general muscular fatigue have an increased susceptibility to the trance. Divide a large homogeneous group of naive volunteers into two equally susceptible sections as nearly as this can be done by means of a battery of tests such as described under No. 3. Lacking the test battery, the subjects could be arranged according to chance. Let the individuals of one group take a long walk which will pretty thoroughly exhaust them. At once following this, subject them to the standard twenty-minute hypnotic technique. Subject the second or control group to the standard hypnotic technique with everything else constant except that they shall not be fatigued. The fatigued subjects should not know or suspect that fatigue is a part of the hypnotic experiment. Probably use trance susceptibility criteria of both projects No. 1 and No. 2. Compare the mean susceptibility to trance of the two groups and determine the statistical reliability of the difference found between the means.

6. Occasional observations suggest rather strongly that persons suffering from loss of sleep are especially susceptible to the trance. This problem could be solved by methods analogous to those described under No. 5. The loss of one night’s sleep by the experimental group would be a convenient unit of privation to employ.

7. Certain drugs are said to increase suggestibility and to favor susceptibility to the trance. Among those worthy of investigation may be mentioned alcohol, chloral, ether, chloroform, and morphine. Perhaps most promising of all is scopolamine. An experimental sqnad of subjects and a comparable control squad of subjects as described under No. 5 would be desirable. In addition it is imperative that a control dose, if possible indistinguishable by the subjects from the actual drug, should be administered to the control group.

It would be especially interesting to test the influence of various drugs upon subjects who had proven refractory to ordinary suggestion. Divide a group of such refractory subjects into two comparable squads and treat as described in the preceding paragraph.

8. It is quite evident to even casual observation that most persons, when about to submit to the hypnotic technique, are in a state of considerable emotional excitement. This may be easily seen, for example, in the beating of the arteries of the neck. This raises the question as to whether the presence of strong emotional excitement facilitates or retards the tendency to fall into the trance.

A large group of subjects such as described under No. 2 should have their emotional reactions recorded as described under No. 25 throughout the initial twenty-minute standard trance procedure. In this manner the mean and the range of intensity of the several emotional reactions should be determined respectively for the three divisions of subjects as regards susceptibility to the trance. A comparison of these means should at least show whether the excitement characteristic of persons about to go into the trance the first time is a favorable or an unfavorable symptom.

9. Subjects who fail to go into the trance often report later that they more or less deliberately resisted the suggestions. On the other hand, tales are sometimes told of traveling hypnotists who are able to hypnotize individuals who at the outset are aggressively defiant. Moreover, subjects responding positively in waking suggestion experiments often report having at first resisted. Some light might be thrown on this problem by securing systematic reports from the various subjects at the conclusion of experiments like Nos. 1, 2, and 8, as to whether they resisted. The percentage of subjects reporting resistance in the various susceptibility groups might indicate something as to the influence of resistance on susceptibility.

It would also be of great interest to see whether the resisting subjects showed more or less than average amounts of the emotional reactions investigated by No. 8.

Unfortunately verbal reports of the nature mentioned above are very easily influenced by various subsequent, and hence irrelevant, factors such as whether or not the subjects actually went into the trance. Probably a much more promising method than that just described would accordingly be for a second experimenter to instruct half of the subjects in a set-up like No. 1 or No. 2, definitely to resist the suggestion. It would be preferable if the hypnotist should himself know nothing about this until after the experimental work should be finished. The mean susceptibility scores of the instructed and the uninstructed groups might easily furnish a useful index of the rôle of voluntary resistance in producing refractoriness to the hypnotic technique.

10. Since the time of Braid, one of the very common methods of inducing the trance is to ask the subject to look fixedly at some bright object held rather close to the eyes and somewhat above, in such a position that the latter are under a certain amount of muscular strain. This is ordinarily accompanied by specific verbal suggestions. Now it is known that verbal suggestions alone will induce the trance. The question arises as to what extent, if any, the optical fixation in itself contributes to inducing the trance.

The solution of this problem calls for three comparable squads of naive subjects. With one group have S look fixedly at the bright object. These subjects should not know that the experiment has anything to do with hypnosis. Accordingly some fictitious but plausible explanation of the purpose of the experiment should be given. With the second group the verbal sleeping suggestion should be given without the optical fixation of the bright object. With the third group both fixation and verbal suggestion should be given as in the usual technique. In all cases the period should be twenty minutes. The criterion of trance susceptibility used in No. 1 and No. 2 could be employed. Compare the mean susceptibility of the three groups, and the differences between the means with the probable errors of the differences. If the differences between the means appear fairly large but are less than two and a half or three times the size of their probable errors, add continuously to the number of subjects in the respective squads until the P.E.’s become as small as desired.

11. From experiments carried out in his laboratory in Petrograd, Pavlov has come to the conclusion that sleep is a highly universal internal inhibition. Here we are concerned mainly with the fact that he has noted certain intermediate states between the waking and sleeping states which he believes to be of the same nature as the hypnotic trance. These experiments should be repeated with human subjects.

Set up a conditioned reflex in which the kneejerk is conditioned to the tone of a tuning fork of 256 d.v. and conditioned not to powers and the other that he is a crude amateur. Subjects from the respective squads will be tested for trance susceptibility in a random order. The hypnotist should not know of the plan of the experiment until it is completed.

15. Various procedures for facilitating the induction into the trance have been employed and advocated from time to time. The relative effectiveness of these various methods should be...