Clever Hans Part 9

[Footnote AD: An ill.u.s.tration is given by Babinet[66] concerning the horse of an English lord. Mr. Burkhardt-Foott.i.t, also, that excellent trainer, who has been master for more than forty of the most highly-trained horses, tells us that while sitting on a well-managed horse it sometimes happened that he had merely thought of making a certain turn, when the horse immediately executed it, before he, the rider, had to his knowledge given any sign or aid. An observation belonging under this head is also made in Tolstoi's "Anna Karenina"[67], this perfect mine of acute psychological observation. In the famous description of the race we are told concerning Count Wronskij riding his Frou-Frou just behind Machotin mounted upon Gladiator, who was leading the race: "At the very moment when Wronskij thought that it was time to overtake Machotin, Frou-Frou, divining her master's thought, increased her pace considerably and this without any incitement on his part. She began to come nearer to Gladiator from the more favorable, the near side.

But Machotin would not give it up. Wronskij was just considering that he might get past by making the larger circuit on the off-side, when Frou-Frou was already changing direction and began to pa.s.s Gladiator on that side." Similar experiences might be gathered elsewhere. Not infrequently the reflection of the rider that his horse had not for a long time indulged in some trick peculiar to him, will immediately call it forth; or doubts on the part of the rider concerning the possibility of crossing some barrier, are often the cause of the horse's fall or of his refusal to leap and of his running away.]

Let us turn now from the consideration of visual perception to that of auditory perception in the horse. We saw that the fact that Hans was able to respond to commands which were only inwardly enunciated, that is, commands which were merely thought of but not spoken, was not proof of great acuity of hearing, but rather that hearing was not at all involved. If Hans had been deaf he would, none the less, have promptly obeyed the commands. Blind and near-sighted horses try to overcome their deficiency by means of the sense of hearing, and hence show a p.r.o.nounced play of ears. In the case of the Osten horse, however, attention has been diverted from auditory stimuli in the process of habituation to visual signs, and as a result ear-movements are almost completely wanting. One is not of course permitted to deny _a priori_ that perhaps some a.s.sociations might have been formed between objects and the vocal signs belonging to them, e. g., between the colored cloths and the names of the colors if both had been presented together oftener than was the case.

But there is a dearth of reliable observation as to how far auditory a.s.sociations of this sort may be established in horses. Usually the following is cited. Horses learn to start off, to stop, and to turn about in response to calls. They are able to distinguish properly between the expressions "right" and "left", or equivalent terms. Upon command they will start to walk, to trot or to run. And they also know the name by which they are usually called. All authors agree that cavalry horses understand the common military commands; one writer even avers that they excel the recruits in this respect.[69] Some believe that in riding schools the horses pay closer heed to the calls of the riding-master than to the control of unpractised riders, even when the two are at variance with one another.[70] My experience with the Osten horse and a number of other pertinent observations aroused in me the suspicion that much that is called or spoken in the process of managing a horse may possibly be just so much labor lost. In consequence I made a series of relevant experiments. I have thus far tested twenty-five horses of different kinds, from the imported Arabian and English full-blood, down to the heavy draft-horse. The experiments were made partly in the courtyard of military barracks, partly in the circus, and partly in a riding-school or in private stalls. I am specially indebted for kind a.s.sistance to Messrs. von Luca.n.u.s, Busch, and to H. H.

Burkhardt-Foott.i.t and E. Schumann, the two excellent trainers connected with the Busch Circus. During these tests, the horses were always amid circ.u.mstances familiar to them, whether free or bridled, under a rider or hitched to a wagon. All aids or signals, except the calls, were eliminated in so far as it was possible.

The results of those tests were in substance as follows: Many horses react to a smack of the lips by a rather fast trot. Many stop on the cry "Hola" or "Brr". This last was nicely ill.u.s.trated in the case of two carriage horses supplied with large blinders and held with a loose rein, and hitched to a landau. One of them regularly stopped when the "brr"

was given by the driver, whereas the other, which had not been habituated to this signal, kept serenely on the trot, so that the vehicle regularly veered off the track--a sure sign that no unintentional aid was being given by means of the reins. Other horses, again, were accustomed to halt in response to a long-drawn-out "hola", but it was the cadence of melody rather than the word that was effective, since any other word, or even a series of inarticulate sounds, would produce the same result, provided they were given with the proper inflection. When this was changed, then the response would fail.

The result was not so apparent when it came to controlling the kinds of gait. One riding-school horse, when lunged and in a gallop, could be induced by a friendly call--the word again was a matter of inconsequence--to slacken his pace into a trot and from a trot into a walk. But this reaction was by no means very precise. Another, a full-blood, contrary to the trainer's expectation and to his great astonishment, failed to respond to any kind of spoken command as soon as the one who carried the reins refrained from making any movements which might indicate what was wanted. (To refrain from all expressive movements of this kind is by no means an easy matter). The slightest move, apart from any help by means of the reins or the whip-handle, was sufficient to evoke a response. The results in the case of the military horses, differed in many particulars. Thanks to the courtesy of Captain von Luca.n.u.s I had the opportunity of testing three cavalry horses, two geldings and one mare, aged nine, thirteen, and nineteen years respectively, and all of them in the regiment ever since their fourth year. They had been selected as the "most intelligent" in the squadron, and we were a.s.sured that they would obey punctiliously all the usual commands. They were ranged behind one another, with the customary distance of two horses' lengths between, and were ridden each by his accustomed rider. Both starting and stopping upon command were tested.

The horses were held by the reins, but the riders were cautioned to refrain from giving any aid that might cause the horse to start when starting was to be tested, or that might restrain him when stopping in response to the spoken command was to be tested. If a suspicion arose--a thing which happened only twice, however--that a rider had actively aided in his horse's reaction, then an officer would mount into the saddle. If it appeared that one of the horses was simply imitating the others, then the others were purposely restrained by their respective riders. The commands were given by the corporal who usually had charge of the horses. In a few cases the sergeant of the squadron gave the commands, but this made no difference in the success of the experiment.

Now as to the results. Whenever the horses were trotting or walking, all commands, without exception, were in vain. They effected neither an increase nor a decrease in the pace. A result was obtained only when the horses were standing when the test began; and this result was simple enough,--upon certain calls the animals would respond by beginning to walk. This was the only reaction that was obtained. The most effective of the commands appeared to be "Squadron,--march!" But the command "Squadron!" or "March!" alone, were quite as effective; yet none of these commands was obeyed without exception. Reactions were occasionally obtained in response to "trot!", "gallop!" "retreat!", (the usual introductory "squadron" was purposely omitted here, because it alone sufficed to start the horses). But the reactions were always the same, viz., to start on a walk. Another series of commands (such as those which are addressed to the rider alone, e. g., "Lances down!") had no effect whatever; a certain amount of selection therefore did seem to take place. In all these tests the order of the horses with reference to each other's position was repeatedly changed. One of the horses, the youngest, and reputed to be the most "intelligent", (he was as a matter of fact the most spirited), gave evidence of a gregarious instinct, intensified by habit, which, if it had been overlooked, might have become a source of serious error. Not being accustomed to go at the head, when so placed it started properly in only 18% of all such cases.

When, however, (other conditions remaining the same,) he was put in second or third place, he started properly in 67% of the tests, and if we take into account only those cases in which the three most effective commands were used ("Squadron!", "March!", and "Squadron--march!") he reacted correctly in 91% of the cases. (The number of tests was 17, 36 and 22 respectively for the three groups mentioned.) The horse, therefore, almost always began to step properly when he stood behind one of his companions, but seldom when he stood at the head. And when he stood at the head and began to walk at the proper moment, it was plain that it was a case of imitation and not initiative, for the horse was still able to see the others, owing to the extent of his field of vision backward, and he was always the last to move, whereas otherwise he was always the first to move, and always difficult to restrain. So when the horses to the rear were restrained or when the intervening distance of two horses' lengths was lessened, so that this gelding could not see the one in the rear, he failed completely to respond. Accordingly these three horses did little to justify the faith which their squadron had placed in them.

Now a few words on the manner in which horses react upon the call of their names. We are not concerned with those that are seldom or never called by name (such as those in the cavalry). I have not discovered one horse that constantly and unequivocally reacted upon the mention of its name (though I would not a.s.sert that there are none that would do so.) I was nearly always able to convince the owners or grooms, who at first had maintained a contrary opinion, that any inarticulate sound was capable of producing the same effect as the calling of the name. What the significance of inflection may be, I am not at all certain. When a certain one of a number of horses standing in the same stable was called, all of them responded by p.r.i.c.king their ears, raising their heads, or else turning about. For this reason the reaction of the horse specifically called lost all significance. Likewise the call which is ordinarily used in lunging when the man in the center of the circle wishes the horse to change its gait, or to advance toward him, also proved ineffectual as soon as the man inhibited every sort of movement.

A slight nod, on the other hand, was always effective. Several times I have tried to call horses to me, when they were free and running about in the arena, but was unsuccessful. After I had given them some sugar, however, they would always come to me--whether I had called or not--and would then refuse to leave my side. But this is a matter of common observation.

I would, however, regard all of these tests as merely provisional. In spite of the greatest effort, it was not always possible to control all the conditions of the experiment, and furthermore, the number of tests would have to be materially increased in order to yield an appreciation of the difference due to race, age, and the individual variation and training of horses. But we may, even now, be sure of one thing. Over against the certainty with which horses react to visual stimuli (in the form of movements perceived), it does not appear that the formation of auditory a.s.sociations is greatly favored by nature in these animals,--indeed, auditory a.s.sociations are far less common than is generally supposed.[AE] Horses compare very unfavorably with dogs in this respect. The latter easily learn to react with a high degree of precision to auditory signs,--as I learned from a series of experiments which I was enabled to perform. The Osten horse, therefore, does not stand alone among his kind in his inferior auditory equipment, as one might be tempted to believe at first blush.

[Footnote AE: All the authors who have given practical suggestions for the training of horses, whether free or with lunging reins, have great faith in the efficacy of calls, but usually recommend a mingling of calls and movements in the way of signs, (thus Loiset,[71] Baucher,[72] von Arnim[73]). It therefore cannot be stated just in how far the calls really effect anything. In other cases I am inclined to doubt outright the influence which is ascribed to the auditory signs. Meehan[74] gives an account of a horse that was exhibited in London in the early 90's of the last century. Pawing with his hoof, this horse apparently was able to count and answer questions in arithmetic, and among other accomplishments he was supposed also to be able to understand something of language. In reality, however, he merely responded to cues which were disclosed to the reporter by the trainer. In pawing, the horse was guided by movements of the trainer, and in nodding or shaking the head he reputedly got his cue from the inflections of the man's voice. Is it not probable that in this latter case it was the movements which accompanied speech that were alone effective in inducing the nod or the shake of the head, so that the exhibiter was deceiving not merely the public, but also himself? Perhaps we may also doubt the exposition made by the well-known hippologist, Colonel Spohr.[75] He tells us that it is easy to train horses to raise the left foot or the right foot in response to the commands "Left--foot!" or "Right--foot!" and that it will be the fore foot when one is standing in front of the horse, and the hind foot if one stands near the rear. It cannot be so very difficult, he thinks, even to get the horse to understand the commands "Left (or right)--fore foot!" and "Left (or right)--hind foot!"--and all without any other aids but the spoken words. Should this really be possible without even the slightest kind of designating movement?----The following case, again, I believe is undoubtedly based upon a misinterpretation. Redding[76] relates concerning his nineteen-year old horse that he himself had owned for thirteen years, and had always kept in single harness,----that this horse not only understood the meaning of a long list of words, such as: bureau, post-office, school, churchyard, apple, gra.s.s, etc., but he also knew a number of persons by name, as well as their places of residence. If he were told in advance to halt at a certain residence, he would do it without any further aid from the driver.

For this reason the happy owner felt certain that the animal possessed a high order of intelligence and "that this horse does reason." What sources of error were here operative, whether signs were given by means of reins, or head or arm movements, could be determined only by a careful examination of the case.

And finally we would exercise some reserve in entertaining the suggestions for the acoustic education of horses which have come from various sources. Colonel Spohr[77] whom we have just been mentioning, thinks that it would not be a difficult matter to get a horse to respond with a walk to one smack of the lips, with a trot to two smacks, and with a galop to three, and then he could be made to slacken his pace once more into a trot in response to one long-drawn "Pst!" and to stop in response to two. Others have gone even further. Decroix,[78] at one time leader in veterinary affairs in France, conceived the idea of working out a universal language as regards the commands that are given to horses, in the humane purpose of sparing them the whip. He called it "Volapuk hippique." For the commands "go," "right," "left," and "halt," he suggests these: "Hi!"

"Ha!" "He!" and "Ho!" respectively. From these it was possible to make eight combinations, such as "Hi! Hi!" for "Trot!" "He! He!" for "Left about" (while the single "He" was to mean "Forward, to the left!") "Ho! Ho!" for "Back!" etc. Decroix thought that the whole system could be inculcated in a very few lessons. He even had a medal struck which was to be awarded to the driver or rider who should first exhibit a horse, thus instructed, to the Societe Nationale d'Acclimatation de France (of which Decroix was president). Eight years have elapsed since then, but we have heard of no one who has earned the medal mentioned. In the future greater care will probably be exercised in the putting forth of such suggestions, and two sources of error may be guarded against, viz.: involuntary movements on the part of the rider or driver, and imitation of the horses amongst themselves. (One horse, guarded by an experienced rider, may serve as copy for ten others with inexperienced men in the saddle.)]

It is easy to explain the musical accomplishments. The tones which were played for the horse, were known to Mr. von Osten, since he himself played the harmonica, or when someone else played it, he, Mr. von Osten, could see the stoppers. He then thought of the number which indicated the tone in question, and Hans would tap it. Thus arose the tale of the horse's absolute tonal memory. This tale gained much support at the time, from an experience which has been recounted to me by the well-known composer, Professor Max Schillings. It shows more clearly than any other report how very confused were the threads that had been spun in the whole matter. In order to test the horse's musical ability Prof. Schillings played, let us say, three tones upon the accustomed instrument. Complying with Mr. von Osten's wish, Prof. Schillings always indicated which three he was about to play. The horse always tapped them correctly. In order to make a decisive test, Prof. Schillings then played, without anyone's knowledge, a note that was in reality a third below the one he had indicated to Mr. von Osten. Curiously enough, Hans tapped, as a matter of fact, the number indicating the note that was actually struck, and it was only in the third repet.i.tion and after many exhortations on the part of the master "to have a care", that the horse finally tapped the number indicating the note Mr. von Osten had in mind and which in truth was the wrong one. This curious experiment seemed to those to whom Professor Schillings communicated it, to yield conclusive evidence of the horse's absolute hearing. As a matter of fact, however, Prof. Schillings had unwittingly, and, contrary to any intention on his part, inspired the horse. Standing, as he did, just behind the right shoulder of the horse, he was able to interrupt Hans (who had begun to tap in response to a move on the part of Mr. von Osten,) by means of an involuntary movement which did the work of a closing signal. At the same time Mr. von Osten, likewise standing to the right of the horse and expecting more taps, remained perfectly quiet. (This is as it was in the tests, mentioned on page 71, in which, of two experimenters, one started the horse tapping, and the other stopped him.) Mr. von Osten very probably lost patience after Hans had seemingly given the wrong response twice, and thereupon came nearer to the horse and thus by monopolizing its attention--so as to exclude Prof. Schillings--he was able to get the response so ardently desired.[AF] When, in tests such as these, two stoppers were opened and thus two notes sounded, Mr. von Osten would count the number of stoppers intervening between the two, and Hans would tap the number. And so arose the tale of Hans's knowledge of musical intervals. Whenever the two notes were sung or whistled, in which case there would be no stoppers that could be counted, then Mr.

von Osten, who was quite dest.i.tute of musical knowledge, was at a loss, and also Hans. If, however, the intervening notes were sung, then everything went smoothly once more. Major and minor chords were regularly characterized as "beautiful", all others as "bad", (but even here errors occurred). A musician had taught Mr. von Osten these distinctions. The old man also knew the melodies that were played on the hand-organ. Each one had a number a.s.signed to it, and Hans was required to tap the number of the melody in token of recognition.--Hans was as ignorant of musical time, as he was of melody, and all attempts to get him to march in regular step were utterly futile. A number of musical tests were made in the absence of Mr. von Osten. In these Mr. Hahn undertook the questioner's role, and since he had had musical training, he was aware of what the numbers should be, even when he could not see the stoppers of the harmonica, and, therefore, we readily understand why it was that the horse responded so wonderfully in his case.

[Footnote AF: General Noizet[79] has left us a story of the middle of the last century, which in essential detail corresponds closely with the one just given. The scene is a French chateau and the hero is--a rapping table, highly prized on account of the intelligent answers it could give. Seated about it were a number of ladies and at the other end of the room sat a French savant, a member of the Academy. The ladies requested him to put a simple mathematical question to the table, and complying with their request, he asked for the cube root of 4. None of the ladies who sat about the table knew the solution; the table unhesitatingly gave 6 raps. This answer was refused as incorrect. The table was asked to try again, and again it wrapped 6. For this it was bitterly reproached. Hereupon the questioner, who during the whole time had remained in his place at the other end of the room, came forward with the confession that the table was innocent, that he had made a mistake. He had asked for the cube root of 4, but had really meant to ask for the cube of that number, viz., 64, and the table had as a matter of fact given the first numeral of that number.

One is immediately struck by the a.n.a.logy between this case and that of Professor Schillings. In both cases those immediately concerned (the women in the one, Mr. von Osten in the other) believe that a wrong answer is being given repeatedly. The cause of the error lies in a person who seemingly is not concerned with the response. (The Frenchman asked the question, but did not sit at the table.

Professor Schillings sounded the notes, but it was Mr. von Osten who got the horse to tap.) In both instances the questioner asks one thing, but had something else in mind. (With the Frenchman it was a slip of the tongue; Mr. Schillings did it purposely.) And finally, in both cases the response corresponds not to the question that has been asked, but to that which has been thought, so that, though seemingly wrong, the responses of both table and horse were really correct. By way of explanation, Noizet believes that he has a case of true thought-transference or "telepathy" (page 108). The questioner watched with utmost attentiveness the rapping of the table, and the women in turn regarded the man. And thus, Noizet believes, the man's thought was transferred to the minds of the others without the mediation of eye or ear, etc., and hence unvitiated by the words that had been spoken. I myself prefer another explanation. At that moment in which the rapping arrived at the expected number, the Frenchman executed a movement characteristic of release of tension and to this the women of the circle reacted. It was not necessary that they should be able to account for this afterward, (just as sometimes occurs in the case of thought-readers[80]). It is very probable, too, that they were not of a very reflective turn of mind anyway. We are warranted, I think, in regarding the two cases as identical in kind.]

The so-called musical ability of horses appears, from all that is known, to be confined within very narrow bounds. Only one fact is universally accepted, viz., horses of the military are believed to possess a knowledge of the significance of trumpet signals, and are often said to interpret them more readily than the recruits.[81] Since no experiments had been made along these lines, I undertook to make a brief test of the cavalry horses mentioned on page 188. As in the preceding tests, the three animals were arranged behind one another with the customary distance of two horses' lengths between, and each was ridden by his accustomed rider. They were held by the reins, but received no aid of any kind, either to start them or to restrain them. A bugle then sounded the various signals at the other end of the barrack's courtyard. We had been previously a.s.sured that the horses would certainly react without fail. But, as a matter of fact, the result was quite the contrary. Two of the horses did not move at all, and the third, a thirteen-year old gelding, was startled nearly every time and would tear off in a gallop--even though a trot had been sounded. I would not, however, venture to draw any conclusions from results such as these. Many more tests would have to be made, and some of them upon the whole squadron, before a judgment could be given.[AG]

[Footnote AG: Professor Flugel,[82] basing his statements on an article appearing in "Sch.o.r.er's Familienblatt" (Berlin, 1890, No. 8, p. 128), gives an account of similar experiments which were supposed to have been conducted by the Zoological Society for Westphalia and Lippe, and presumably showed that "the horses of the military do not understand the bugle calls." No matter how well trained a horse may have been, it would not respond to a signal. This report, however, is due to a mistake. Such experiments have never been made by the society mentioned, so I am told by its director, Dr. Reeker. Nor do I know of any one else who has made experiments of this kind.

However, Professor Landois,[83] the eminent zoologist, now deceased (founder of the scientific society mentioned), tested four circus-horses for their musical ability and specifically for their sense of musical time. He arrives at the conclusion that horses "have no feeling for time, whatsoever." With but few exceptions,[84, 85] all experts to-day are of the same opinion.

Horse-trainers, especially, are universally agreed on this point. It is easy to see in any circus performance that it is not the horses that accommodate themselves to the music, but that the music accommodates itself to them, and that the trained horses[86] are induced to do their artistic stepping only by the aids given by their riders. Furthermore, all these horses are trained without the use of music.----It would therefore appear that the time had arrived when the tales of the dancing horses of the Sybarites ought no longer to gain credence. Two Greek writers, Athenaeus[87] and aelian,[88] tell us that the inhabitants of Sybaris, far-famed for their luxurious habits, had trained their horses to dance to the music of flutes during their banquets. Building upon this, the men of Crotona, in one of their campaigns against the Sybarites, ordered the flute-players to play the tunes familiar to the Sybarite horses.

Immediately the well-trained steeds began to dance, thus throwing the whole Sybarite army into confusion, and the men of Crotona won the day. (The same story is told in more detail concerning the horses of the inhabitants of Cardia. Both accounts, somewhat mixed, are to be found in Julius Africa.n.u.s,[89] a writer of the third century of the Christian era.)--In recent years a French veterinary surgeon, Guenon,[90] experimented on the effect of music upon the horses of the military. He entered their stalls, playing upon a flute, and noted their behavior. Four-fifths of the animals, he says, were deeply moved, yes, delighted, even, ("charmes." One interpreter[91] calls it a case of hypnosis!). This emotional excitement was expressed--somewhat unaesthetically--by the dropping of excrementa. Guenon characterizes the feeling-state of these animals as being a mixture of pleasure and astonishment, of satisfaction and excitement ("melange de plaisir et d'etonnement, de satisfaction et de trouble.") He also a.s.serts that the horse's musical taste is similar to our own. But I can find nothing in his whole exposition which might prove this. Indeed there is nothing that could be interpreted as anything other than a purely sensuous effect upon the horses. I may go a step farther and say that thus far the sense of music, i. e., understanding of melody, harmony and rhythm, has not been shown to exist in any animal. Some animals may, however, be susceptible to the sensuous pleasantness of the tones themselves.]

I shall now turn to peculiarities of character, highly humanized, which have been attributed to Hans. His "sympathies" and "antipathies", so-called, were nothing but erroneous appellations for the success or failure on the part of the respective individuals to elicit responses.

He who could procure answers frequently, apparently stood high in the horse's favor. That Hans shook his head violently when asked by Mr. von Osten: "Do you like Mr. Stumpf?", and answered in the affirmative the further question: "Do you like Mr. Busch?", was nothing but a confession--unwilling, to be sure--on the part of the master himself. In the first case the master thought "no", in the second instance, "yes", and the two thoughts were accompanied by the corresponding head movements, to which Hans responded mechanically. Hans appeared to be well-disposed toward me, but evidently because I always rewarded him liberally when he answered correctly, and I did not scold him when his responses were wrong, as did Mr. von Osten and Mr. Schillings, who instead of seeking the cause within themselves, were always ready to rebuke Hans for his contrariety and fickleness. The horse did not show, in so far as can be judged at all, any real affection for his master. On the other hand it would be unwarranted to say that, in spite of all rewards, he developed a grudge against all those who bothered him with instruction and examination. Shortly after the close of our experimentation it happened that Hans severely injured his groom by a blow in the face. Yet this man had always been very gentle with the horse and had been forbidden by Mr. von Osten to make Hans solve any problems for him. Experts a.s.sure me that we have here to deal, not with a case of "moral insanity", but with a very common experience,--although this view will probably be cavilled at by enthusiastic lovers of horses.

The work of so excellent an expert as Fillis,[92] for instance, bears us out in this respect.

The horse's supposed fickleness was nothing but a token of the fact that even those who were accustomed to working with him, did not have him completely in hand. (They simply did not understand how to obtain correct responses from the horse.) It often happened that in the evening, when it had become so dark that the movements of Mr. von Osten could no longer be seen, Hans had to suffer bitter reproaches because he made so many errors. That, in truth, he never was stubborn and that the cause of failure really lay in the questioner, is shown by the fact that the mood, for which he was reproved, would disappear the moment the questioner voluntarily controlled the signals. We may add that there was no basis for the a.s.sumption that "he had an uncommon, finely const.i.tuted nervous system" or was possessed of a "high degree of nervousness". Both these phrases were often mentioned by way of explanation. Hans was restive, as horses usually are. And besides, he lived a life so secluded (he was never allowed to leave the courtyard) that as a result he was easily disturbed by strange sights and sounds. There was not the slightest trace of the clinical symptoms of neurasthenia--on the contrary he gave the impression of perfect health,--which was curious enough when we remember his rather unnatural mode of life.

Hans's stubbornness was a myth. He was suspected of it whenever the same error occurred a number of times in succession, i. e., when the questioner did not properly regulate his attention (page 146) or when he was being controlled by "perseverative tendency", mentioned on page 149.

Mr. Schillings, who has provided me with material here as elsewhere, relates the following episode which occurred on one such occasion. To one and the same question put alternately by Mr. von Osten and Mr.

Schillings, Hans responded correctly, with two taps, to the former, and just as persistently incorrectly, with three taps, to the latter. After Mr. Schillings had suffered this to occur three times he accosted the horse peremptorily: "And now are you going to answer correctly?".

Hereupon Hans promptly shook his head, to the great merriment of all those present. (Mr. Schillings had, with no accounted reason, expected a "no".) Hans was called willful whenever the same question was successively answered by different responses, as frequently happened with the increasing tension that characterized the high numbers (page 145). He was also regarded as stubborn when no reply at all was forthcoming, as in the tests with the blinders.

Hans's supposed distrust of the questioner, when the latter did not know the answer to the problem, is nothing but a poor attempt to account for the failure of those tests. Hans's distrust of the correctness of his own responses was supposed to be evident from his tendency to begin to tap once more if, after the completion of a task, the questioner did not immediately give expression to some form of approval or disapproval--just as a schoolboy begins to doubt his answer if the teacher remains silent for a short time. In terms of the results of our experimentation this would mean that whenever the questioner did not resume the erect posture, after Hans had given the final tap with the left foot, then the horse would immediately begin once more to tap with the other foot (page 61).

As the evil characteristics, so, too, the good. Thus, his precipitancy, which was supposedly evidenced by his beginning to tap before the questioner had enunciated the question, was nothing but a reflection of the questioner's own precipitancy in bending forward (page 57). Never did Hans evince the slightest trace of spontaneity. He never spelled, of his own accord, anything like "Hans is hungry," for instance. He was rather like a machine that must be started and kept going by a certain amount of fuel (in the form of bread and carrots). The desire for food did not have to be operative in every case. The tapping might ensue mechanically as a matter of habit--for horses are to a large extent creatures of habit. This lack of spontaneity could hardly be reconciled with the horse's reputation for cleverness. It would not be necessary to touch upon the signs that were supposed to betoken genius: the intelligent eye, the high forehead, the carriage of the head, which clearly showed that "a real thought process was going on inside",--all these, we said, would not need mentioning, if they had not been taken seriously by sober-minded folk. If there is a report that Hans turned appreciatively toward visitors who made some remark in praise of his accomplishments,--it is evidence only of the observer's imaginativeness.

Turning from a consideration of the horse to that of the persons experimenting with him,[AH] the first and most important question that arises is this: How was it possible that so many persons (there were about forty) were able to receive responses from the horse, and many of them on the very first occasion? The answer is not hard to find. All of these persons came to the horse in very much the same frame of mind--which found a similar expression in all, in both posture and movements. And it was these motor expressions of the questioner (aside from the signs for "yes" and "no", which I believe I have adequately explained on page 98), that the horse needed as stimuli for his activity.

[Footnote AH: I cannot enter upon a discussion of the latest psychological problems, here involved, partly because that would take us beyond the purpose of this monograph, and partly because they are still moot questions and hence not suited to popular treatment. Briefly though, they are these: What is the nature of the relationship between cognitive and affective states on the one hand and involuntary, (so-called expressive) movements on the other? Is this connection an external thing, as it were, an a.s.sociation arising as a habit formation, or does every idea partake essentially of a motor character? Do purely cognitive states give rise to such movements, or does the movement impulse depend more particularly upon the affective consciousness accompanying the cognitive states?

And in how far do given kinds of expressive movements depend upon certain ideational types (c.f. page 95)? Thus, what is the influence of the visual image upon the gestures for "up," "down,"

etc.? And then, are these involuntary movements, when not noted, truly unconscious, or merely not attended to,----in other words, are they beyond the pale of consciousness or merely "at the fringe?" The various writers speak almost without exception of unconscious movements in the strict sense of the term. My own introspections, however, have led me to doubt whether they are quite unconscious.

Since I have attained some practice I am able to describe in detail (under conditions of objective control) my involuntary movements, no matter how slight, even down to mere muscular tensions. None of my subjects, however, has as yet succeeded in this. It is no very easy matter to be on the lookout for some unknown movements which might eventually occur, while attempting to concentrate attention to the utmost upon a certain definite ideational content, for this very dividing of attention effects a decrease in the force of the movement, and thus makes it all the more difficult to discover. From my own experience, however, I am inclined to believe that these movements are not unconscious, but merely unattended to, in other words, we have a narrowing down of the apperceived content within certain limits, but not a narrowing down of consciousness, (much less a "splitting" of consciousness or of personality as the thing unfortunately has sometimes been called). In order, however, not to be guilty of premature judgment, I have avoided the terms "unconscious" and "unattended to," and chose expressions which leave these finer distinctions untouched.]

The next question that arises is: why did only a few persons receive responses regularly from Hans, whereas the greater number were favored only occasionally? What was the selective principle involved? The answer is, that the successful person had to belong to a certain type, which embodied the following essential characteristics.

1. A certain measure of ability and tact in dealing with the horse. As in the case of dealing with wild animals, such as the lion, etc., Hans must not be made uneasy by timidity in the questioner, but must be approached with an air of quiet authority.

2. The power of intense concentration, whether in expectation of a certain sensory impression (the final tap), or in fixing attention upon some idea-content ("yes", "no", etc.). It is only when expectancy and volition are very forceful, that a sufficient release of tension can ensue. This release of tension is accompanied by a change in innervation and results in a perceptible movement. And it was only when the thought of "yes", or "up", etc., was very vivid, that the nervous energy would spread to the motor areas and thence to the efferent fibers, and thus result in the head-movement of the questioner. From infancy we are trained to keep all of our voluntary muscles under a certain measure of control. During the state of concentration just described, this control is relaxed, and our whole musculature becomes the instrument for the play of non-voluntary impulses. The stronger the customary control, the stronger must the stimuli be which can overcome it. The steady unremitting fixation, which resulted in the horse's selection of the cloths, also involves a high degree of concentration.

3. Facility of motor discharge. Great concentration was necessary of course, but not sufficient. Persons in whom the flow of nervous energy tended to drain off over the nerves leading to the glands and the vascular system might betray great tension, not so much by movements as by a flow of perspiration (we have many excellent examples of this given by Manouvrier)[93] or by a violent beating of the heart, blushing and the like,--in short, by secretory and vasomotor effects. Or it is not inconceivable that long dealing with very abstract thoughts might have weakened the tendency of overflow to other parts of the brain, and that therefore the entire discharge is used up in those portions of the brain which are the basis of the intellectual processes. But if expressive movements occur, the motor pathways must be particularly unresisting in order to take up the overflow of psychophysic energy. This is the necessary condition for obtaining the tapping and the head movements on the part of the horse, although for the tapping there is still one other circ.u.mstance necessary: viz.,

4. The power to distribute tension economically--i. e., the ability to sustain it long enough, and to release it at the right moment (after the manner of the curves described on page 93), and to control properly the unavoidable variations which will occur.[AI]

[Footnote AI: The mental state just described is probably essentially the same as that of the spiritualistic "mediums" when they are occupied with table-rapping and table-moving. In both cases concentration is very intense,----in other words, the field of attention is limited. We saw that this state not only favors the tendency toward involuntary movement, but on account of the absorption of the individual's attention by a certain limited content, the person will be unaware of the voluntary movements as they occur. And we are not necessarily here dealing with neurasthenic, hysteric, or other diseased nervous conditions. In the case of table-rapping there are movements of the hands, in our case there are those of the head. Our head, balanced as it is upon the cervical vertebral column, is continually in a state of unstable equilibrium and therefore peculiarly susceptible to movement-impulses of every kind. But I could induce not only movements of the head, but also of the arms and legs, and this by having the subject a.s.sume a posture which enabled him to hold arms or legs in as unstable a position as possible. He might stretch out his legs horizontally before him, or he could raise them vertically upward as in the hand-stand in gymnastic work. An extract from a treatise by Count A. de Gasparin,[94] which appeared about the middle of the last century, may serve to show how close the correspondence between the two processes, that of getting the table to rap and that of causing Hans to respond, really is. The report of this writer, based upon the detailed record of his tests in table-moving and table-rapping, closely parallels in many minute details the observations which were made in the course of our experimentation with Hans. The case is all the more remarkable when we bear in mind that this writer did not seek the cause of the phenomena, as we did, in involuntary movements, but thrusting aside this explanation, he posited the cause in the agency of some mysterious fluid. It may not be amiss to say that this as well as most other references were consulted after the present experiments and introspections had been completed. Of the page references preceding the following citations, the first always refers to the page in the French original, and the other, enclosed in brackets, to the parallel pa.s.sage in the present monograph.

P. 49 [31]. Some questioners are especially suitable ("experimentateurs hors ligne"), but in their absence, other persons may also operate successfully ("le succes, quoique moins brillant alors, n'est pas impossible.")

P. 25 [229]. But even the most suitable questioners do not always succeed equally well ("les plus surs d'eux-memes ne reussissaient pas egalement tous les jours.")

P. 42 [151]. When the questioner is in any way indisposed, the measure of success is also less.

P. 91 & 87 [150]. The Questioner must first get into the sweep of things ("en train"), and once he has done so, all interruption whatsoever must be avoided.

P. 91 [93]. Unless there is sufficient tension on the part of the questioner, the test will fail. ("La volonte est-elle absente, rien ne bouge.")

P. 210 [93]. When there is too low a degree of tension, then too great a number will be tapped ("si votre volonte ne les [les tables]

arrete pas au moment ou se termine le chiffre pense, elles continueront indefiniment.")

P. 31 [93]. But too great concentration of attention will also produce failure ("s'il n'arrivait ... de desirer trop fortement le succes et de m'impatienter en cas de r.e.t.a.r.d, je n'avais plus aucune action sur la table.")

P. 36 [151]. If the proper mood ("entrain habituel") is wanting and the tests are unsuccessful, it is best not to attempt some new and difficult experiment, but to turn to some that are simpler and more entertaining ("La table obeissait mal; les coups etaient frappes mollement et comme a regret.... Alors nous avons pris un parti dont nous nous sommes bien trouves; nous avons persevere, et persevere gaiement; ... nous avons ecarte la pensee des tentatives nouvelles, et insiste sur les operations aisees et amusantes. Apres un certain temps les dispositions etaient changees, la table bondissait et attendait a peine nos commandements.")

P. 199 [41, 90]. It is not necessary to enunciate the questions aloud ("On est convenu que celui qui commanderait ne p.r.o.noncerait pas a haute voix le nombre de coups, mais se contenterait de les penser, apres les avoir communiques a l'oreille de son voisin. Eh bien! la table a obei. Il n'y a jamais eu la moindre erreur.")

P. 199 [64 ff.]. The large numbers are tapped more rapidly than the small ones ("la table a indique notre age tel qu'il etait dans notre esprit, se hatant meme de la maniere la plus comique lorsque le nombre des coups a frapper etait un peu considerable.")

P. 210 [35 ff.]. Tests in which "procedure was without knowledge"

failed completely ("Les tables ne revelent pas ce qui n'est pas dans la pensee et dans la volonte de l'experimentateur; quand on veut les charger d'autre chose que d'obeir comme des membres, on arrive a des erreurs continuelles.")