Fact and Fable in Psychology

by Joseph Jastrow

IV

What is the origin of the movements involved in these records? To what extent are they movements of the hand, of the arm, or of the entire body? Casual observation is sufficient to show that with a given position of the arm, certain movements are much more readily made than others; and the involuntary tendencies will naturally follow the lines of least resistance. If, for instance, you hold your arm nearly on a level with the shoulders and in line with them, you perceive at once that movements of the hand to the front are much more readily made than to the rear, and movements toward the body more readily than those away from the body; the tendency of the hand is to move forward in a circle of which the shoulder is the centre. What we require is a position in which movements in any one direction are as readily made as in any other; and this may be approximated, though only approximated, by holding the hand at an angle of about 45° with the line joining the shoulders, and with the elbow bent at an angle of about 120°. This was the position in most of the tests, and the usual result was a movement toward the object of attention; but when the object attended to lies in back of the subject, this tendency is sometimes outweighed by the natural tendency for the arm to move forward, and the result may be a movement forward, but a less direct movement forward than when the object of attention is to the front. In a good subject, however, the involuntary tendency is strong enough to prevail, and a movement backward results. An instance of this, obtained under other but comparable circumstances, appears in Fig. 14. It is to be noted that in this figure the tracing marked I. was obtained with the subject seated, and the metronome beating behind him; the hand after some hesitation moves backward slowly towards the metronome to a moderate extent. In tracing II., with the subject also seated, the metronome is to the front, and the hand moves directly and quickly towards it. We conclude that the position of the body is an important factor in the resultant movements, but that it does not interfere with their accepted psychological interpretation.

Fig. 14.—Counting the strokes of a metronome. Subject seated. In tracing I. the metronome is at the rear. Time of record, 105 seconds. Direction of the attention ←. Subject facing →. In tracing II. the metronome was to the front. Time of record 45 seconds. Direction of the attention →. Subject facing →. ⅘ size.

Fig. 15.—Counting the strokes of a metronome. Time of record, 45 seconds. The upper tracing shows the movements of the head recorded upon a plate resting on the head. The lower tracing shows the usual record of the hand upon the automatograph. Direction of the attention →. Subject facing →.

When observing the subject during a test, we may note the movements of the body as a whole, and of the arm or hand. The movement of the body is an irregular swaying with the feet as the centre of the movement; this swaying is most readily recorded by fixing the recording-plate upon the subject's head, and having the recording-rod held in a suitable position above it. It was found that in connection with the swaying movements there were general movements towards the object of attention; and such movements were as readily made when the object was to the front, to the rear, or to either side. To determine how far this movement is the same in head and hand, it is necessary to record both simultaneously. Fig. 15 illustrates the correspondence of the two movements. It thus becomes clear that the swaying of the body as a whole constitutes an important factor of these automatograph records; that the movements of the head (being farther away from the centre of motion) are more extensive than those of the hand; and that both head and hand are sensitive organs for the expression of involuntary movements. That the muscle-reader is aware of this fact is obvious from the usual positions which he maintains towards his subject in reading the direction of the hidden object.

Fig. 16.—Counting the strokes of a metronome. Right hand holds the pencil, and left hand holds the record plate. Direction of metronome →. Subject facing →. In the upper tracing the subject was standing; time of record, 90 seconds. In the lower tracing the subject was sitting; time of record, 90 seconds.

Fig. 17.—Thinking of a building. Right hand holds pencil, and left hand holds record plate. Subject facing ↑. In tracing I., direction of the attention ↑; in tracing II., direction of the attention ↓. Time of each record, 60 seconds. II. shows respiration records.

Fig. 18.—Counting the strokes of a metronome. Right hand holds pencil, left hand holds record plate. Direction of the attention from A to B ↑, from B to C →, from C to D ↓, from D to E ←. Time of each portion, 45 seconds.

To eliminate the record of the swaying of the body, we may experiment with the subject seated; we obtain a distinctive record in which certain phases of the fluctuations have almost disappeared, and in which the record approximates to a straight line (tracing II. of Fig. 14). One may also eliminate the record of the swaying by dispensing with the automatograph, and simply holding the recording plate in one hand and the recording device or pencil in the other; for then the plate and pencil sway together, and naturally no record of it is made. The relatively fine movements thus obtained are shown in Fig. 16; the contrast between this record and such records as Figs. 4, 5, 6, is mainly the contrast between a record in which the general swaying of the body is registered, and one from which it has been eliminated. It is interesting to note that in records thus taken, there is but a slight difference in the result when the subject is standing and when he is sitting; which is a further proof that the swaying of the body has been eliminated. (Compare these with Fig. 14.) Traces of periodic oscillations are noticeable in Fig. 16; these are due to movements of respiration, and in tracing II. of Fig. 17, they are unusually distinct and regular, about twenty to the minute. In this case the forearm of the hand holding the record plate was braced against the body, while the recording hand was held free from it; and thus the abdominal movements were registered. The movements toward the object of attention appear throughout. Fig. 17 shows a movement towards the rear of the subject, as well as towards the front; which again shows that under suitable conditions, involuntary movements may be recorded in one direction as readily as in another. Fig. 18 presents a most beautifully regular movement in all four directions. As the metronome, the strokes of which the subject was counting, was carried from one corner of the room to another and so on around the room, the hand involuntarily followed it and recorded an almost perfect square. So striking and regular and so varied an involuntary movement, in conformity with changes in the direction of attention, one can expect to secure but seldom, and then only with a good subject.

Fig. 19.—Thinking of a building. Both hands hold record plates, the pencils being held fixed above them. Time of record 35 seconds. Direction of the attention ↓. Subject facing ↓. I., left hand: II., right hand.

The outline presented in Fig. 19 was obtained in a test in which the movements of the hands were separately recorded, in order to determine the degree of correspondence between them. The result shows a marked general resemblance, indicating in part a common origin of the two movements. The next figure, Fig. 20, shows that this correspondence is dependent in part upon the similarity of the positions of the two hands. The hand that is held away from the body moves more extensively; but the form of the movements remain similar. The records reproduced in Figs. 14-22 and 26 were obtained upon the same subject, though with slightly varying conditions, and are fairly comparable with one another, and thus illustrate the analysis of the resultant movements into their component factors.

Fig. 20.—Thinking of a building. Each hand holds record plate. Time of record, 35 seconds. Direction of the attention ↓. Subject facing ↓. I., left hand held extended far out. II., right hand held close to body.

Fig. 21.—Thinking of one's feet. Record plate vertical. Time of record, 45 seconds. Direction of the attention ↓. II., thinking of a point overhead. Time of record, 45 seconds. Recording plate vertical. Direction of the attention ↑.

Involuntary movements are not limited to the horizontal plane; vertical movements may be recorded by holding the recording device in a slanting position, and fixing the record plate upon the wall. The main characteristic of such a record is the sinking of the arm through fatigue; the movement is rapid and coarse (tracing I. of Fig. 20). If the attention be directed to the front, we obtain a resultant of the tendency to move towards the object of attention, and of the sinking of the arm, as appears in the diagonal line of Fig. 22. Fig. 21 illustrates an interesting point similar to that illustrated in Fig. 14. When the attention is directed downward, the hand falls rapidly (tracing I.); but when the attention is directed upward, very little movement at all takes place,—the tendency to move towards the object of attention constantly counteracting the tendency for the arm to fall (tracing II.).

Fig. 22.—Counting the strokes of a metronome. Record plate vertical. Pencil held in extended right hand. Time of record, 20 seconds. Direction of the attention ←. Subject facing ←.