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Extra-Sensory Perception, by J. B. Rhine, [1934], at


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.

Next: Appendix to Chapter 15. Suggestions to Those Who May Care to Repeat These Experiments