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]
The experience of a number of practical men, who have had much to do with horses and yet achieved but very modest success with Hans, goes to show that it is not always the lack of sufficient authoritativeness, mentioned under heading 1 that is the sole cause of failure, as has been claimed so often. That the horse was, to a certain degree, influenced by this element of authority is shown, however, by the following incident. A certain gentleman, when alone in the courtyard with Hans, received responses only so long as I (concealed in the barn) kept the barn-door open just a little, so that my presence could be known to the horse. As soon as I closed the door, Hans refused to respond to the gentleman. Those who possessed sufficient power of concentration and the requisite motor tendency—the two characteristics mentioned under 1 and 2 above,—were able to obtain responses from the horse without any previous practice. Practice merely effected a more economic distribution of attention, so that the larger numbers especially were more successful as a result (pages [68] and [89]). Those who were lacking in either of the characteristics mentioned under 2 and 3 would not be aided even by the greatest amount of practice, as is shown by the case mentioned in [Supplement III (page 255)].—That many individuals were at first successful but were later unable to get any successful responses, is to be accounted for by the fact that the power of concentration, at first present, later rapidly disappeared. This temporary increase in the power of doing mental work was first investigated experimentally by Rivers and Kraepelin,[95] and was called by them "Antrieb" and aptly likened to the first pull of a team of horses in starting off. This, too, explains an experience which befell a number of the horse's visitors, who later described it to me. Wishing to utilize a momentary absence of Mr. von Osten, they excitedly put a hasty question to Hans, and with amazing regularity received correct responses.—Besides Mr. von Osten, Mr. Schillings and myself, not many were always able to induce Hans to bring the colored cloths or to execute the head movements. It was easy, on the other hand, to get him to nod. Therefore there was some truth in Mr. von
Osten's assertion, that Hans would be unable to answer a difficult question if he had not previously indicated by means of a nod that he had grasped its import. Those who were not concentrating sufficiently, would not look into Hans's face, when he was expected to nod, and would not bend over, when Hans ought to begin tapping—such persons could not, therefore, since they did not induce Hans to nod, elicit the tapping. I, myself saw the "no" successfully elicited only in the case of Mr. von Osten, Mr. Schillings and Mr. Hahn; the "right" and "left" only in the case of the former two. It must remain uncertain whether this failure on the part of otherwise suitable persons to elicit the responses for "right" and "left" was due to their accompanying these ideas by movements of the eyes instead of by movements of the head, ([page 106]). For unfortunately it was not possible to make special tests to discover whether Hans reacted to isolated eye movements. There is, however, more than one reason why I would doubt this. Taken all in all, there were but few persons who were entirely representative of the type described (c. f. [page 31])—they were those who are commonly characterized as being of a lively temperament and strongly impulsive. Thus Hans acquired a reputation for "Einkennigkeit", that is, he would accustom himself only to certain persons. Such a reputation was hard to reconcile with his much praised intelligence.
In closing, just a word on the influence of the public that was present. As was shown on [page 69], the public in general did not influence the horse in his reactions. The effect upon the questioner, however, was unmistakable, and worked in a twofold manner. On the one hand the questioner's zeal was increased and with it the tension of concentration. On the other hand, it introduced an element of diversion, and attention was divided between the horse and the spectators, and thus concentration suffered. If the disturbing effect was slight, as in the case of Mr. von Osten, then the favorable influence exercised by the presence of the public outweighed the unfavorable. Mr. von Osten was, for that reason, often particularly successful when working in the presence of a large body of spectators. This was noted by many and was ascribed to the ambition of the horse. When, however, a person was easily diverted, as was Mr. Schillings, then the presence of the public had a less fortunate effect.
This, then, completes my explanation of the facts gleaned from observation and experimentation. It accomplishes all, I hope, that may be expected of an explanation. All the known achievements of the horse, all the successes and failures of the questioner, have been reduced to a single principle; no secondary hypothesis has been invoked, and but slight place has been given to the element of chance. Nevertheless, it may not be out of place to forestall two objections which might possibly be raised. First, some may assert that it was through our experimentation that the horse became mechanized and incapacitated as regards conceptual thinking; that formerly he really could solve arithmetical problems, and only later developed the very bad habit of depending upon the signs which I gave him. This objection is to be refuted in that I did not originate these signs, but first noted them in Mr. von Osten, himself, and in that Hans still works as faithfully as ever for Mr. von Osten. I have learned from many trustworthy witnesses that the horse still continues to give brilliant exhibitions of his "ability". If, on the other hand, anyone should assert that it was only with us that Hans reacted to movements, but that with his master he really thought and still thinks, then I must ask for proof. This latter argument is by no means very original. When Faraday in 1853 proved experimentally that "table-rapping" is the result of involuntary movements on the part of the participants standing about the table, the spiritualists asserted that his experiments had nothing in common with their own proceedings, because his subjects (who by the way, had been up to that time firm believers in table-rapping) probably did move the table, they said, while they (the spiritualists) do no such thing.[96]
FOOTNOTES:
[T] Professor Shaler[24], a well-known American savant, mentions a three-year old pig belonging to a Virginian farmer, that was able to read and had some understanding of language. From numerals which were written upon cards and spread out before it, this pig could compose dates. It could also select from among certain cards one upon which was written a given name, asked for by the master. Supposedly no signs of any kind were given. (Shaler thought to exclude effectively the sense of smell, which is so highly developed in the pig, in that he, Shaler, himself smelled at the cards, since he also "possessed an acute olfactory sense!") Since we are told that the farmer in question made a business of supplying trained pigs for exhibition purposes, the case appears suspicious. We hear of a pig exhibited in London, that was able to read and spell, and could also tell the time by the watch[25]. We cannot tell, however, whether the two pigs, which beyond a doubt were mechanically trained to respond to signals, are identical or not.
[U] It has been scientifically proven that a number of supposed mystical phenomena, table-moving, table-rapping, and divination by means of the rod, all are the result of involuntary movements made unawares by those concerned, just as in the case of this work with Hans. (We must of course except those not infrequent instances in which the phenomena in question are purposely and fraudulently simulated.) There is this difference, however, that there the thing affected is a lifeless object,—the table or the rod,—here it is a living organism, the horse; hence there the immediate effect of the movement is physical work in the form of energy expended in moving the table, here the movement becomes a visual stimulus. A number of observations which I find in the relevant literature, and which I shall introduce into this chapter, may serve to show how close is the similarity between the two cases, how much depends upon the questioner, and how little really upon the instrument—whether table or horse—which is acted upon.
Two examples will suffice to illustrate the significance of belief and of the concentrated attention that results from it. The first is taken from the letters of Father P. Lebrun on the divining rod[26], which appeared in 1696. An old woman once told a treasure-seeker that she had always heard that a treasure was buried at a certain place in the fields. The man, who was known as an expert in the art of using the divining rod, immediately set out to locate the gold. Lo, and behold, the moment he set foot on the spot described by the old woman, the branch turns downward, and from its movements the man gathers that twelve feet below ground there lies buried some copper, silver and gold. He calls a peasant to dig a pit eleven feet deep, then he sends him away so that no other should get into the secret. He himself digs a foot deeper, but all in vain, for he finds nothing. Standing in the pit, he again takes up the branch. Again it moves, but this time it points upward, as if to indicate that the treasure had disappeared from the earth. Dismayed, he climbs out of the pit and questions the branch a third time. This time it points downward once more. He climbs back into the pit. Presently he feels the prick of conscience (for in the 17th century many regarded the dipping of the divining rod as the work of the Devil). Terrified, he exclaims: "O God, if the thing I am doing here is wrong, then I renounce the Evil One and his rod (s'il y a du mal, je renonce au démon et à la