Another fact that must be borne in mind is that, when once a spectator has seen a movement made two or three times in the same manner, he frequently "sees" the performer make that movement on another occasion, when the performer had, in reality, only STARTED to make the movement, and suggested the rest. Thus, if the performer throws a ball up into the air two or three times in succession, and on the fourth occasion merely pretends to throw it up, really retaining it in the other hand, the great majority of the spectators will really "see" the ball ascend into the air on the fourth occasion, and will so state, on being asked. We here depend upon association and habit.[1]
[1] A very similar illusion is mentioned by Professor Hyslop, v. Borderland of Psychical Research, Pp. 228-9, in which pellets were apparently placed in a box, really being palmed in the medium's hand.
Professor Jastrow summed up this portion of the psychology of deception very well when he said:[1]
[1] Fact and Fable in Psychology, pp. 124-5.
"He (the conjurer) must dissociate the natural factors of his habits, actually attending to one thing while seemingly attending to another; at the same time his eyes and his gestures and his 'patter' misdirect the attention to what is apparently the essential field of operation, but really only a blind to distract attention away from the true scene of action. The conjurer directs your attention to what he does not do; he does not do what he pretends to do; and to what he actually does, he is careful neither to appear to direct his own attention nor to arouse yours."
Prof. Max Dessoir, in a very fine article on "The Psychology of Conjuring," writes as follows: "By awakening interest in some unimportant detail, the conjurer concentrates that attention on some false point, or negatively, diverts it from the main object, and we all know the senses of an inattentive person are pretty dull. . . . When causing the disappearance of some object, the conjurer counts one, two, three; the object must really disappear before three, not at three, because, the attention of the public being diverted to three, they do not notice what happens at one and two. . . . A specially successful method of diversion is founded on the human craze for imitation. . . . The conjurer counts on this in many cases. He always looks in the direction where he wants the attention of the public, and does everything himself which he wants the public to do. . . . If the trick is in the left hand, the conjurer turns sharply to the person to his right, presuming correctly that the spectators will make the same movement, and will not notice what is going on in the left hand. . . . Every sharp, short remark will, for a moment, at least, divert the eyes from the hands and direct them to the mouth, according to the above-mentioned law of imitation."
The successful conjurer has carefully studied beforehand every movement that is made—every word that is spoken—during a conjuring performance, and has seen that these all fit naturally into place, and help conceal the real workings of the trick. The right and left hands must be trained to operate independently, and without the need of looking at either. Many conjurers practice doing two separate things at the same time, one with either hand; and the ability to do this is essential. Above all, the performer must be full of conscious self-possession, and feel himself to be master of the situation, no less than to feel the ability to cope with any emergencies that may arise.
Turning, now, to a consideration of the seance, we find that many of these psychological rules still hold good, and their operation enables the medium to perform many actions which would otherwise be impossible. A certain suggestion is given to the sitters, and imagination and inference do the rest. "Our conclusions as to what we see or hear are always founded on a combination of observation and inference; but in daily life it is seldom necessary to distinguish between the two elements, since, when the object and its mode of presentation are familiar, our inferences are generally correct. But it is different when, owing to circumstances, such as a bad light, we have to infer more in proportion to what we perceive than usual; or when some one, e. g., a conjurer or a ventriloquist, is trying to deceive us by presenting one object under the familiar aspect of another, and suggesting false inferences. It is not uncommon to find people at seances encouraging each other in the belief that they see, say, a living human figure, when all that they actually SEE is something moving which is about the size of a human being; the rest is inference." How true these last remarks are is demonstrated by the statement, made in The Revelations of a Spirit Medium, that an old wire mask frequently used at materializing seances had been recognized "by dozens of persons as fathers, mothers, sisters, brothers, cousins, sweethearts, wives, husbands, and various other relatives and friends. None but the medium knew that it was only a fifty-cent wire mask, hence none but the medium could enjoy the humor of the occasion."
One of the most instructive incidents I know, in relation to this question of the psychology of deception, is the one given by Doctor Hodgson[1]—the case of the officer and the Hindu juggler. In this case, a trick was performed before an English officer and his wife, and Doctor Hodgson happened to overhear this officer telling some travelers of the experience at dinner that evening. "Referring to the movements of the coins, he said that he had taken a coin from his own pocket and placed it on the ground himself, yet that this coin had indulged in the same freaks as the other coins. His wife ventured to suggest that the juggler had taken the coin and placed it on the ground, but the officer was emphatic in repeating his statement, and appealed to me for confirmation. He was, however, mistaken. I had watched the transaction with special curiosity, as I knew what was necessary for the performance of the trick. The officer had apparently intended to place the coin upon the ground himself, but as he was doing so, the juggler leaned slightly forward, dexterously and in a most unobtrusive manner received the coin from the fingers of the officer, as the latter was stooping down, and laid it close to the others. If the juggler had not thus taken the coin, but had allowed the officer himself to place it on the ground, the trick, as actually performed, would have been frustrated.
[1] Proceedings Society for Psychical Research, Vol. IV., pp. 385-6.