Extra-Sensory Perception - (15) Summary and Concluding Remarks

31.08.2014 18:05


Summary and Concluding Remarks

It seems likely that a table summarizing the general totals of those chapters giving the main figures would be of some convenience to the reader here. There are two columns showing X-values 1 (anti-chance) for the results, the last column giving that obtained by formula and the next to


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the last, the X-value given by the pooled results. The formula method is,

I believe, the more proper, but figures of both are so high as to leave dispute pointless. Also there are included in these totals all the results of all experiments, even those made with a view to reducing the score-level (drug experiments, etc.). However, in the low-score work of Stuart and Pearce in which they purposely reversed the calling, I change the negative sign of deviation to positive in pooling these results with the others. There were altogether 1,575 of these. The average successes per 25 trials are given in column 4.

Several thousands of test data have accumulated as I have worked at this manuscript but these cannot be included in the totals here without some description of conditions; furthermore, it seems very doubtful if any one can have the appetite for more of these figures. I need only say that these data are in general in line with those already presented and would alter no conclusion offered here, if fully incorporated.


General Summary of the Results of E.S.P. Tests to August 1, 1933

in Chap.

Conditions, etc.

No. of

No. of

No. Hits
per 25
np. 5






p=½, ¼, 1/10, 1/26,
etc. Misc. subjects









p=1/5 Misc. subjects









p =1/5 Linzmayer









p =1/5 Stuart









p =1/5 Pearce









p =1/5 Five Major Subjects









p =1/5









All values of p









1. It is independently established on the basis of this work alone that Extra-Sensory Perception is an actual and demonstrable occurrence.

2. E.S.P. is demonstrated to occur under P.C. or pure clairvoyance conditions, with not only the sensory and rational functions, but telepathic ability as well, excluded by the conditions.

3. E.S.P. is also demonstrated to occur equally well under P.T. or pure telepathy conditions, with clairvoyance excluded along with the sensory and rational cognition.

4. E.S.P. occurs equally well and at similar levels of scoring in both P.C. and P.T., as shown by actual measurement, using equal probabilities and similar general conditions. The reasons are many for believing that in P.C. and P.T. the same general mental function is at work.

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(a) All major subjects, except one, 1 have ability in both P.T. and P.C.


(b) Their results, individually and totally, are of nearly the same scoring-level in both P.T. and P.C.

(c) Daily fluctuations in both take the same direction, preponderantly.

(d) Both are affected in the same way and in approximately the same degree by sodium amytal.

(e) Caffeine affects both in the same direction.

(f) Both function with considerable distances between percipient and perceived (agent or object).

(g) Both show with distance, when the subject can work at all above np, a rise in scoring-rate over that achieved in the same room.


These and other similarities all strongly favor the belief (though I do not say they establish it) that in P.C. and P.T. we have to do with a common underlying process, capable of functioning in the cognition of two different perceptual units, mental activities (images in these tests) and material objects (card figures). No differentiating circumstance whatever has been discovered contrary to this belief.

5. The Wave theory seems to be inapplicable to these results, in view of the distance experiments and the absence of any decline of results with distance. The assumption that the wave theorist must make—namely, that the ink-figure would radiate the same waves as the active mind of the agent—is fantastic. A further difficulty for wave theories is found in the D.T. work, which ought, on that theory, to give a hopeless jumble of waves. These and other difficulties compel the rejection of the wave-theory—which is the only type that modern physics has yet to offer.

6. Likewise it is shown that E.S.P. is not a sensory phenomenon. The absence of any need of orientation, of any sensory localization, of any recognized stimulating energy such as the senses receive and of any awareness of reception all lead to the rejection of the sixth sense hypothesis as well. E.S.P. shows also much greater need for integration than does the sensory level of mental processes.

7. At the same time, the definite volitional control over E.S.P. shown by all the percipients, the large role of effort and voluntary attention apparent in all, the retarding effect of dissociative drugs and other factors all tend (first) to exclude the hypothesis that the percipient is a mere passive receptor of an incorporeal agent's intruding action, and (second) to make E.S.P. a part of the natural organization of the species. E.S.P. is directed by the conation of the percipient, and integrates naturally with the other cognitive and with the affective processes of the percipient's mind.


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1. Good abstraction is required for success in most percipients, along with effort and attention to the task; in a word, "concentration".


(a) New changes in procedure may disturb this for a time.


(b) New visitors as witnesses are likely to do so for a time.

(c) Conflict of purposes (and, of course, emotions) spoil concentration.

(d) Dissociation lowers, along with other functions, the capacity to concentrate.


2. Since E.S.P. harmonizes with the other mental processes and adds its function as a less restricted mode of perception, it can conceivably have great practical personal value.

3. E.S.P. would seem to possess, potentially, a considerable biological (species survival) value. It may be inferable from the drug data that it is a later evolutionary acquisition, as evidenced by its higher organization, which is in turn indicated by its easier disturbance by amytal and fatigue. This chain of inference is none too strong and may be put down, not as a "point" but as an "impression".

4. It seems favorably suggested, at least, that E.S.P. may be heritable or perhaps its more common inhibiting factors may be.

5. The loss of E.S.P. ability with long use is the exception rather than the rule. The ability may decline and return. It may also decline with the daily run.

6. E.S.P. may run consistently below chance expectation if there is unconscious (and, of course, if there be conscious) negative tendency of sufficient strength.

7. The "curves of operation" found are probably motivational in origin. There is evidence that interest, effort and attention vary, and cause results to vary; there is no clear evidence yet that E.S.P. ability per se varies.

8. Improvement in E.S.P. is limited, usually to a short initial period; and this may be purely a matter of learning to abstract and achieve good concentration. There is no good evidence of improvement of the ability. A level seems to be reached and not far exceeded. When it is exceeded for particular runs it seems to be through special effort.

9. Variation of the procedure, without introducing new changes, helps to keep up the scoring level. Encouragement is usually helpful. Light humors and moods are the best in which to work at E.S.P.

10. There are many facts supporting a view that E.S.P. is easily encroached upon by rational and sensory processes, and that the delicate balance required for good E.S.P. may be concerned chiefly with the maintenance of the field of attention free from these encroachments. Perhaps

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this is why improvement is shown so uniformly with distance (i.e., when complete failure does not attend it). Distance discourages sensory attention and would aid abstraction.

11. The following laws or relations seem to hold between agent and percipient, but the evidential support is as yet not fully adequate, particularly so for No. 3:


(1) Good E.S.P. ability in both agent and percipient seems to give highest results.


(2) Good E.S.P. ability in the percipient with poor ability in the agent gives mediocre results.

(3) Poor E.S.P. ability in the percipient, regardless of what the agent may be like, does not give results above chance.


12. E.S.P. is not easily fatigued. In P.T. the agent tends to suffer from fatigue, but the percipient does not.

13. Loss of E.S.P. ability by an occasional subject may be due to incapacitation for the necessary abstraction under the conditions, rather than a loss of the E.S.P. function itself.


1. The general impression is given by the life histories of these major subjects that there may be a general connection between E.S.P. and many other parapsychological phenomena. This may at least, be offered as a working hypothesis.

2. The distance data, along with the general facts, suggest the freedom of mind in E.S.P. from the common material relations of extension or distance. This would mean the "de-materialization" of mind operating under these conditions. This is psychologically important, as bearing upon the question of the body-mind relation, upon personality-survival and some of the other questions in the natural philosophy of mind.

3. The large role of conation evidenced in E.S.P., the failure of the radiation laws to apply to its phenomena and the fact that P.C. scoring is as good as P.T., along with the accuracy attained in D.T. at short distances and in B.T. at longer ones, all suggest the view that the percipient's mind "goes out" to the object or mental act that is to be perceived, and that this projection of mind is a peculiarly non-mechanistic procedure, since by the latter theoretically there would be no projection—simply radiation on a spherical front, with intensity declining with the square of the distance.

4. E.S.P. influences other processes that direct overt behavior and hence it affects, however indirectly, the recognized doing of work. This is itself doing work, however little it may be. It is thus inescapably "energetic" (even as the physicist means the word—"capable of doing

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work"). We have, then for physical science, a challenging need for the discovery of the energy mode involved. Some type of energy is inferable and none is known to be acceptable, since wave mechanics are inapplicable to the case.

5. Likewise, the challenge may be given to physiology that a new mode of energy reception is required—reception of an unknown energy form by an unknown mode of reception. It involves the nervous system quite as much as does any other cognitive process, as judged by drug effects and other physiological evidence.

6. In psychology E.S.P. is a possible spurious factor in the experimental laboratory, a possibly helpful one in hypnosis and in therapy, a requisition for the expansion of our concepts of the place of mind in nature and a lead to understanding the energetic principles of general mental life. It may, too, be an innate ability, since certainly there is no evidence of its being acquired; i.e., no evidence of real development.

7. There seems to be in this work thus far a "species level" of E.S.P. ability reached by most subjects and not much exceeded, on the average, over large numbers of trials. The evolutionary origin and the biological survival value of E.S.P. are problems at which we have only hinted possible answers.

8. One is tempted to point, as a final suggestion, to the analogies of E.S.P. found in religions and mystic lore, and to refer to the apparent applicability of the principles of E.S.P. to some religious "experiences" and claims. Might we not find good E.S.P. subjects in the medicine-man, the mystic and the prophet?


161:1 See Appendix to Chapter 2, page 32.

163:1 Later this exception was eliminated when Zirkle became successful in B.T. as well as in P.T., and at roughly the same rate.





Suggestions to Those Who May Care to Repeat These Experiments 1

It is hoped that others will repeat these experiments or, better still perform more advanced ones. Much depends upon the conditions of the tests as to whether success or failure will follow. The following suggestions along with the discussion in Chapter 12, may help to avoid failures:

1. The subject should have an active interest in the tests and be fairly free from strong bias or doubt. These would, of course, hinder effort and limit attention. An open-minded, experimental attitude is all that is required. Positive belief is naturally favorable but not necessary.


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2. The preliminary tests should be entered into very informally, without much serious discussion as to techniques, or explanations or precautions. The more ado over techniques, the more inhibition is likely; and the more there is of explanation, the more likely is introspection to interfere. Playful informality is most favorable.

3. If possible to do so honestly, it is helpful to give encouragement for any little success but no extravagant praise is desirable, even over striking results. The point is that encouragement is helpful, apparently, but only if it does not lead to self-consciousness. If it does, it is quite ruinous. Many subjects begin well, become excited or self-conscious, and then do poorly.

4. Some begin more easily with P.T. and some with P.C. It depends upon personality, I think, but I cannot explain it except to link sociability with P.T. preference. However, both conditions should be tried, following the subject's preference in the beginning.

5. It is highly important to let the subject have his own way, without restraint, at first. Later he can be persuaded to allow changes, after he has gained confidence and discovered his way to E.S.P. functioning. Even then, it is better for him to have his way as far as experimental conditions can allow. It is a poor science that dictates conditions to Nature. It is a better one that follows up with its well-adapted controls and conditions.

6. It is wise not to express doubts or regrets. Discouragement seems to damage the delicate function of E.S.P. Here again no doubt personalities differ. One subject, I know, has worked in the face of doubt expressed; but she is exceptional in this.

7. Above all, one must not, like several investigators, stop with only 25 or 50 or even 100 trials per subject. Most of my good subjects did not do very well in the first 100. With few exceptions, the first 50 to 100 trials give the worst scores. With all my major subjects this is true. Several different occasions or sittings, too, should be allowed, for there is with most subjects an adjustment phase at first that may take some time.

8. It is best at first to have the subject alone with the agent in P.T. and in P.C. to leave him alone entirely. If not, he may be inhibited from the start; but, once he has a start, he can gradually work back to other conditions. When he has observers present, the experimenter should do all he can to put the subject at ease.

9. Simple cards with 5 suits seem best as a compromise of several features of concern: easy calculation, easy recall, easy discrimination of images, etc.

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10. Short runs are desirable, say 5 at a time, with a check-up after each 5. Then it is best to go casually and quietly on without too much discussion of results.

11. It is advisable not to bore or tire the subject. When he wants to stop, or even before he expressly wishes to, it is better to stop work.

12. It is best to try good friends for P.T. at first—or couples, single or married, who feel certain they have thought-transference; and, above all, to try those people who say they have had "psychic" experiences or whose ancestors conspicuously have had.

These are suggestions, not rules, for we do not yet know enough of the subject to lay down rules. They will help toward success, without endangering conclusions. One can always tighten up on conditions before drawing conclusions later. But any investigator must first of all get his phenomena to occur—or exhaust the reasonable possibilities in trying to.


166:1 The views of Mrs. Sinclair given in Mental Radio and already mentioned should be read by those interested in this phase. See also the abstract and discussion of Mrs. Sinclair's report by Dr. Prince, in B.S.P.R. Bulletin XVI.



Second Appendix to Chapter 15 1

Throughout this report the values of groups of data have been presented in the form X=D/p.e. In the beginning of the experiment this ratio was important as a proof of the inadequacy of the chance hypothesis. When the values grew far beyond the limits of any available tables the X ratio was useful mainly as an arbitrary quantitative measure of differences between blocks of data and between the work of individuals. These X ratios may serve their original purpose as anti-chance ratios, however, if any reader still clings to the Chance Hypothesis.

The following table (Table XLIV) gives an approximation to the meaning in terms of chance probability of the X values listed in Table XLIII [10-14 means 1 fourteen places to the right of the decimal point (.000 000 000 00001). This gives odds of 100 thousand billions to one against mere chance as an explanation. It is left to the reader to write out the figure corresponding to 10-1220.]


Chance Probability of X Valises













































The figures given are rough approximations computed by using only the coefficient of the series expansion for the probability integral. 2 As



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the error of such an approximation is less than the last term used in the series, and as we have used only the first term, 1, the error in P is equal to the figure given; that is, an error of 100%. This would be a serious error in a pay envelope or cost estimate, but with these tiny ratios it is negligible. For example: if X = 20 the approximation would give P = 10-40.744, but with an error of 100% the actual value of P may lie anywhere between 10-44.443 and 10-∞. As we are here concerned with only the upper limit of the error the difference between . (40 zeros)18 and . (40 zeros)36 is considerably less than the errors introduced by our using only two and three significant figures in the tabulation of the exponents. 1

And a final word of warning to the mathematical enthusiast. Mathematically the difference between X = 20 and, let us say, X = 40, is enormous beyond our capacity to experience. For that reason, for the purpose of evidence in opposition to a Chance Hypothesis the difference is simply too superfluous to be appreciated. The higher values do give the experimenter a quantitative measure of comparison and a feeling of comfortable certainty, but the skeptic who refuses to be convinced by a value of 15 or 20 will scarcely be moved by any mathematical treatment of the data whatever.






168:1 I am indebted to Mr. Charles E. Stuart, Graduate Assistant in Psychology, for this Appendix, as well as for much assistance in the earlier mathematics of the production. He has been, as mathematician, assistant, and subject, an extraordinarily useful and competent man.

168:2 The formula is given in Rietz, H. L.: Handbook of Mathematical Statistics. P. 15.

169:1 This paragraph may be regarded as primarily for mathematicians since it would require much space to make it clear to the layman. It simply justifies the approximation-method used in measuring the odds against chance implied by a given X-value. Since few men have ever required such odds for establishing belief in a principle, the tables are not available; and the computation by more exact methods would be a burdensome—and a uselessly burdensome—task.