"Inhalt", "Mass", and "Zahl", (form, content, measure, and number), and each of them I accompanied, with a certain definite arm movement. The subject always pronounced the word inwardly as emphatically as possible, but without ever imaging the corresponding arm movement. Often, it must be noted, she did not know whether or not the movement which I made was the proper one. And yet she, too, soon fell into line in the matter of executing unconsciously the characteristic head movements. In a total of 50 tests, I was able to make 10 correct guesses in the course of the first 20 tests, 8 in the next 10 tests, and 19 in the last 20 tests. Miss von L. noted only a few of her upward head-movements, viz.: those that were especially pronounced (movements through about 2 millimeters), but of the others she knew nothing. The same experiment was repeated with a psychologist, well-trained in introspection, as a subject. Success was even greater here. But no matter how closely the subject observed himself, he was unable to solve the puzzle.
Variations which were introduced in these tests, I will only mention in passing. Thus, instead of making an arm movement, I, in some cases, would tap with my foot, for "Ibis" once, for "Kiebitz" twice. The subject could not see my feet. The involuntary movement-expression which became associated with "Ibis" was one nod of the head, with "Kiebitz" two nods, etc. Here our only
concern was to show that unconscious change in natural expressive movements and the acquisition of artificial ones are possible in the case of psychically normal subjects trained in introspection.
I was not satisfied with convincing myself subjectively of the facts indicated, but sought to fix them objectively, by means of a graphic method. For this purpose I used the device mentioned by Prof. R. Sommer for the analysis of expressive movements.[18] The purpose for which Prof. Sommer's apparatus had been constructed, was to record the involuntary tremor and movement of the hand. These movements, of course, take place in the three dimensions of space. By means of three levers it is possible to record the movements upon the flat surface of a smoked paper fastened to the revolving drum of the kymograph, the movements in each direction being recorded by a separate lever, in such a way that the three curves thus made represent the analysis of a single movement into its three dimensional components. By making slight changes, which tended to complicate the experiment somewhat, I adapted the apparatus to the measurement of movements of the head. The method of experimentation was the following. The subject whose movements were to be registered, was placed in the device in such a way that his trunk and head were bent slightly forward, the latter a little more than the former. This, it will be remembered, was the usual position of the questioner when working with the horse. Three levers were attached to his head in such a way that every movement backward or forward would act upon the first lever, every movement to the right or left would move the second, and every movement of the head upward or downward would be recorded by the third. With regard to the sensitivity of the machine, micrometric determination showed that when the subject was properly installed, movements through so small a distance as 1/10 millimeter could be accurately ascertained. The subject was carefully instructed to remain as quiet as possible, but without constraint. Voluntary movements were thus obviated. But the question arose: were not the involuntary movements thus suffering a loss?—And it was upon them that we were experimenting. The question cannot be put aside summarily, but experience taught us that the movements in question, nevertheless, did appear quite effectually, if one could have the right kind of subjects at one's command. We need hardly mention that besides the two persons immediately concerned—I, myself, attended to the apparatus—there was no one else present, and that the subject was not allowed to see the curves produced on the kymograph. Besides the registration of the head-movements, I also undertook to register the respiratory-movements of the subject. This was done by means of the so-called pneumograph, attached to which was a lever recording the thoracic expansion and contraction. This was for the purpose of ascertaining the relationship, which might eventually be found to exist, between the release of psychic tension, on the one hand, and respiration, on the other.
The subject was now told to think of some number, which, of course, was unknown to me. At a given moment I was to tap upon one of a series of keys arranged like those of a piano, with the middle finger of my right hand—corresponding to the right forefoot of the horse. The questioner observed my key, I, his head,—just what had happened in the experiments with Hans,—and as soon as I perceived the involuntary closing signal I reacted upon it by releasing, suddenly, another key upon the same keyboard, which I had in the meantime been pressing down with my second finger, thus marking what with Hans had been called the backstep. Each key was connected with a separate electro-magnet, and these in turn with markers, in such a manner that pressure upon the keys closed two electric circuits and, releasing the keys, opened them, and both the closing and the opening were recorded upon the smoked paper by means of the markers. And, finally, in order to ascertain the time relations of all these processes, a time-marker indicated the time in fifth-seconds upon the revolving kymograph record. The time-curve was recorded just below the other curves.
Of the curves[P] thus obtained under the most equable conditions possible, we publish seven which show the great general uniformity of the tests made upon the horse with those made in the laboratory. The rôle of questioner was undertaken at different times by Mr. Schillings and the students of philosophy, Messrs. von Allesch, Chaym and K. Zoege von Manteuffel. To all of them I am greatly indebted for their unselfish services in these laborious tests. The experiments with von Allesch and Chaym, who were among the most suitable of my subjects, were conducted absolutely without knowledge on their part of the nature of the phenomena which I was observing. Neither of them knew anything about the expressive movements in which they were unconsciously indulging, and furthermore, since they kept their heads bowed during the entire course of these experiments, they did not perceive what it was that I was observing. It is interesting to note that Chaym on the occasion of his only visit to the horse, immediately received a number of correct responses. Without a doubt von Allesch would have met with equal success. The other two subjects (von M. and Sch.) went through this series of tests, possessing some knowledge of the nature of the movements involved. Conditions were such that they (and especially Mr. Schillings) could not be prevented from obtaining some knowledge of the essentials, at least. However, it would be wrong to suppose that for this reason the results were more favorable, owing, mayhap, to voluntary efforts on the part of the subject. The contrary was true. The two subjects who had no knowledge of the character of the reactions upon which my responses depended, retained their normal habits, unchanged, throughout the series,—whereas the last-named two, afraid lest their knowledge vitiate the result, lost more and more of their power of concentration and within a short time were in a condition of tense inhibition, which is all the more conceivable, since they had had no psychological training whatever.[Q]
Their movements, which at first were quite profuse, decreased more and more, so that in the case of von Manteuffel the percentage of my successful responses sank from 73% correct responses in 90 tests to 20% in a total of 20 tests,—and in the case of Schillings from 75-100% to 23% in a series of 35 tests. The curves obtained with von Manteuffel as subject, which I am here publishing (figures [8] and [15]), are, however, true to his normal habits. The same is true of the two first curves of Schillings (figures [10] and [11]), whereas the third ([figure 12]) shows distinctly the traces of the state of inhibition into which he fell, and represents the same condition as when Mr. Schillings, while preoccupied, tried to work with Hans. All the finer details of the phenomena in question, were likewise unknown to these two subjects.
For purposes of a clearer understanding of the various curves, [figure 5] is inserted to give the general scheme of their arrangement.
