not hitherto been proven experimentally regarding any other species,
nevertheless something of this sort has been known concerning the dog
for some time. His ability to single out an object upon which his master
had intently fixed his gaze, was made the basis of a special form of
training, called "eye-training,"[56] nearly one hundred years ago. The
dog was taught to focus constantly upon his master's eyes and then upon
command to select the object which he, the master, had been fixating.
Such a dog has been described by the naturalists A. and K. Mueller.[57]
But the master of the dog, unlike Mr. von Osten, would not permit anyone
else to work with the animal, and the two brothers, recognizing the
trick, were justified in adding that "the whole affair aimed at
deceiving the public, and the dog's reputation was but a means of making
money". The success of such exhibitions appeared furthermore, to depend
upon the close proximity of the trainer and the dog, whereas the
direction of the head (and even of the body) could very probably be
perceived at greater distances also. At least we learn from a reputable
source that in the hunt, dogs can perceive from the mere posture of
their master, what direction he intends to take.[58]
But a still more curious fact is this, that dogs, too, learn--evidently
spontaneously--to react to the minimal involuntary expressive movements
of their master. The first example mentioned in the literature on the
subject is that of an English bull-dog called Kepler, belonging to the
English astrophysicist, Sir William Huggins.[59] We are told that this
dog seemingly could solve the most difficult problems, such as
extracting square roots and the like. The numbers were indicated by
barking,--thus one bark was for one, two barks for two, etc. Every
correct solution was rewarded with a piece of cake. Huggins states
explicitly that he gave no signals voluntarily, but that he was
convinced that the dog could see from the questioner's face, when he
must cease barking, for he would never for an instant divert his gaze
during the process. Huggins was unable, however, to discover the nature
of the effective signs. This satisfactory, though still unproven,
explanation has been accepted by specialists, among them Sir John
Lubbock.[60] I, too, regard this dog as a predecessor of our Hans.
A similar case is reported by Mr. Hugo Kretschmer, a writer of Breslau,
in the "Schlesische Zeitung" of August 21, 1904. To him I am beholden
for a detailed written statement, which he has kindly permitted me to
use in this connection. The gentleman named, first trained his dog to
ring the table-bell, and this, by pressing the dog's paw upon the
bell-button. When the dog had learned to do this independently, his
master tried to teach him the rudiments of numbers, in such a way that
the animal was to give one ring of the bell for the number 1, two for 2,
etc. But these attempts failed utterly and had to be abandoned. But Mr.
Kretschmer had noticed that he was able to get the dog to ring any
number which he, Mr. Kretchmer, might decide upon. (Success was always
rewarded by a bit of bread and butter.) At first Mr. Kretschmer tried to
imagine vividly only the final number, but failed thereby to elicit
correct responses from the dog. But he did succeed when he tried making
a series of separate volitions. Thus for the number 5, he would "will"
each separate push of the button on the part of the dog. Even so,
however, he never got beyond 9, for then the dog would become impatient
and would ring the bell continuously. Anything that diverted the dog's
attention, such as noises, etc., also entailed failure. In these tests
master and dog had faced each other, each gazing steadfastly at the
other. Mr. Kretchmer was convinced, however, that the dog was not guided
by any sort of sign, but rather by suggestion. He based his belief on
the following two observations. After some practice, he says, the tests
were also successful when he did not look at the dog, but stood back to
back with it, or when he screened himself from the dog's view by
stepping to one side behind a curtain. The tests were unsuccessful, on
the other hand, whenever he was mentally fatigued or had taken some
alcoholic drink. The arguments do not appear to me to be adequate. If he
turned his back upon the dog and no other observer was present, he had
no means of knowing whether the dog did not, after all, peer around to
get a peep at him. If others who knew the desired number, were present,
the dog might have gotten his cues from them. And there may be some
doubt whether the curtain adequately served the purpose for which it was
intended. At any rate, it was added that all attempts to influence the
dog from an adjoining room--which would thus exclude effectively all
visual signs--were utter failures. I am also strengthened rather than
weakened in my belief, by the second argument which Mr. Kretschmer
makes, viz.: that mental fatigue or the use of alcohol on the part of
the questioner tends to make the result unsatisfactory. We noted a
similar effect in the case of the horse (page 150), where a disturbance
of the "rapport" between the questioner and the horse was invoked by
some by way of explanation. The facts were explained by us much more
simply. We attributed the result to the close correlation between the
type of mental concentration and the nature of the expressive
movements--a correlation which we have shown experimentally to exist. I
cannot, therefore, subscribe to the view that this dog did not require
either visual or other sensory signs. The tests which were made for the
purpose of strengthening that view, are on a par, I believe, with those
mentioned on page 45. And since auditory, olfactory, and other stimuli,
though not impossible, still are improbable, I believe that our Hans,
Huggins's dog, and the one belonging to Mr. Kretschmer, differ from one
another only in this, that the first taps, the second barks, and the
third presses a bell-button.
And finally I have access to a letter from the Rhine Province in which
there is a brief account of a dog that would promptly obey any command
that was given without a sound and supposedly without the accompaniment
of the slightest kind of gesture. It is specially mentioned that the
animal steadily watched its master during these tests. The perception of
the slightest involuntary expressive movements is in all probability the
secret in this case also. Here, too, suggestion has been invoked by way
of explanation, but there was not the slightest attempt made to find for
it a more specific foundation, and we cannot suppress an objection based
on the matter of principle. It is incumbent upon anyone who uses a term
so ambiguous, to define what content he desires to have put into it. If
he does not do this, he is giving us, instead of a concept, a bare word,
instead of bread, a stone.
While we must reject the explanation based on suggestion,[AC] we
believe, on the other hand, that we have here again, evidence of the
presence of visual signs, given unwittingly and involuntarily, just as I
am sure that they were involved in the two preceding cases, and
similarly in the case of the Huggins dog. Since the effective signs were
discoverable in none of these canine predecessors of Hans, an
investigation would be desirable, based upon the insight gained as a
result of these experiments upon Mr. von Osten's horse. Unfortunately
this is impossible, since the dogs in question are dead. But others like
them undoubtedly exist in many places. We might mention that when Hans
first came under the limelight of public attention, there was also
frequent reference to the Huggins dog, but he soon dropped out of the
discussion again.[63] And this for two reasons. The dog never took his
gaze from his master and appeared to be entirely dependent upon him in
his reactions. Hans, on the other hand, seemed to give evidence of a
high degree of independence and never appeared to look at the
questioner. But we know now that, though he was never dependent upon the
will of his master, he, too, abjectly hung upon the man's involuntary
movements and never for a moment lost him from view. But since the horse
is able to observe with one eye alone, and needed to direct only it and
not the entire head toward the questioner, in order to focus
comfortably, one could not conclude as to his line of vision from the
direction of the head. Since, furthermore, in the horse the pupil is
hardly distinguishable from the darkly pigmented iris and since the
white sclerotic is hidden by the eyelids, except when the eye is turned
very much, it is difficult to determine what direction the eye is
taking. I once purposely stepped backward to the horse's flank, so that
he had to turn his eye far back and thus the outer border of the iris
and the white sclerotic coat became visible and all doubt concerning the
line of vision was removed. This doubt could never arise in the case of
the dog, the median plane of whose head is always directed toward the
object fixated, and Zborzill is justified in saying, as he does, in his
discussion of training of the kind mentioned on page 177, "But any
careful observer can immediately guess the manner in which such a dog
has been trained."[64] If Hans had chanced to possess so-called
"glass-eyes"--in which the dark pigment is wholly or partly lacking, so
that the black pupil is clearly defined against the lighter
background,--then no doubt could ever have arisen concerning the
direction of the eye, and Hans never would have come to be regarded as
the "clever" Hans.
[Footnote AC: I can find examples of supposed suggestion in the case
of animals given only by Rouhet.[61] He says that by means of
suggestion he taught a half-year old half-blooded mare-colt which he
had raised himself, to fetch and carry, and this in a very short
time. In order to indicate to the colt what was wanted, Rouhet would
concentrate with his whole mind upon the object intended (a watch),
and at the same time he would bend forward slightly. In the third
test, that is at the end of fifteen minutes, he had accomplished his
purpose, and in the tenth lesson, no more mistakes occurred. The
colt would fail to respond, however, as soon as he refrained from
making any gestures, or was in a laissez faire frame of mind, or
when he thought of other things. He therefore believes that there
must have been some kind of immediate, though inexplicable,
connection between the brain of the trainer and that of the horse. I
think the explanation is evident: the connection was not as he
thought, an immediate one, but arising through the mediation of the
man's attitude ("attitude un peu baissee"), and of his movements
("gestes"), both resulting from his intense concentration ("tension
de la pensee").
In general we may say that, no matter what content we may wish to
put into the term "suggestion," not a single fact has since come to
light which would justify, and much less demand, the application of
the term to lower forms, unless we would expand the definition of
the term to the extent of comprising every kind of command, every
arousal of ideas, whatsoever. But it would then be nothing but a new
name for old knowledge[62] and would lose all explanatory value.
(Hypnotism, so-called, in the case of horses, I shall discuss
elsewhere in another connection.)]
After the publication of the December report, Hans acquired a reputation
for excellence in thought-reading and thus the discussion of
thought-reading among animals in general became once more the order of
the day. That is to say that many of our domestic animals are--like the
human mind-reader (a la Cumberland),--supposed to have the ability to
infer the thoughts of their masters from slight, involuntary movements.
They are thus aware when the feeding hour approaches, when they may go
out in the open, etc. They also appear to be aware that their welfare
lies in our hands, and therefore would seem to have a vital interest in
divining our intentions and our wishes. Not only our spoken words, but
also numberless movements--usually without our knowing it and often
contrary to our desire--speak a clear language. As is well said by the
American neuropathologist, Beard,[65] (who first explained the
phenomenon of thought-reading, on the basis of the perception of very
minute muscular jerks, and therefore called it "muscle-reading" or
"body-reading"): "Every horse that is good for anything is a
muscle-reader; he reads the mind of his driver through the pressure on
the bit,--though not a word of command is uttered." We know that in the
case of perfectly trained horses the rider's mere thought of the
movement which he expects the horse to make, is seemingly sufficient to
cause the animal to execute it.[AD] Such cases are of course very much
like that of our Hans, excepting that instead of visual signs they
involve aids of a mechanical nature, which, however, does not alter the
general principle, since both of them are of the nature of sensory
stimulation. But we must not overlook the essential difference between
this so-called thought-reading on the part of animals and that which is
done by man. The human thought-reader can interpret movements, for he is
familiar with the ideas which are their source. Thus when at the second
tap, I notice a very slight jerk of the subject's head, and a stronger
one at the fifth tap, I infer that he thought of the problem 2+3=5.
While the experimenter thus cannot be said to read thoughts, he still
infers them. The animal, on the other hand, we may be reasonably sure,
draws no such inferences. In its conscious life it remains ever on the
sensory level. If we could ask Hans about it, he would probably answer:
"As soon as my master stoops forward, I begin to tap; as soon as he
moves, I stop. The thing which induces me to act thus is the carrot
which is given me; what it is that induces my master to make his
movements, I do not know."--It is therefore erroneous to believe that
animals require the power of abstract thinking in order to utilize the
signs which are consciously or unconsciously given them, as is argued by
Goldbeck[68] when he says with reference to the training for visual
signs, which we have already mentioned before: "There the dog has
consciously interpreted the visual impression in terms of the conclusion
that he is expected to bring forth the leaf indicated." Nor was there
any justification for the critic who thought he could put the essence of
the report of December, given in Supplement IV, into the following
words: "He (Hans) showed that he has the power of attention, can draw
logical conclusions, and can communicate the result of his
thinking,--and all this independently." Yet none of this had been
asserted. The whole thing may be explained satisfactorily by means of a
process of simple association established between the signs observed in
the master and certain reactions on the part of the horse. The fact that
the movements made were so exquisitely minute does not change the matter
in the least. Such signs call for a high degree of sensory keenness and
great concentration of attention, but by no means an "extremely high
intelligence."
[Footnote AD: An illustration is given by Babinet[66] concerning the
horse of an English lord. Mr. Burkhardt-Foottit, 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 pass
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 pronounced
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 associations 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
associations 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 assistance to Messrs. von Lucanus, Busch, and to H. H.
Burkhardt-Foottit and E. Schumann, the two excellent trainers connected
with the Busch Circus. During these tests, the horses were always amid
circumstances 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 illustrated 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 Lucanus 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 assured 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 assert 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 pricking 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 associations is greatly favored by nature in these
animals,--indeed, auditory associations 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, grass, 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 "Volapuek 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 repetition 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 destitute 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 assigned 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 analogy 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 assured 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 Fluegel,[82] basing his statements on an
article appearing in "Schorer'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 Africanus,[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 asserts 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 assure 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 assumption that "he had an uncommon, finely constituted
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 association
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
circumstance 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 assume 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 passage 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 retard, 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 prononcerait
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.")
P. 28, 29, 217 [72]. When of two experimenters each tries to get the
horse to tap a different number, then that one who is the better
able to compel the animal's attention, will be the successful one.
("L'un veut faire prevaloire un chiffre pense plus considerable,
l'autre un chiffre pense moins considerable.... Eh bien: l'operateur
le plus puissant l'emporte." "Ainsi A est charge secretement de
faire frapper 25 coups, B est charge secretement de l'arreter a 18;
A l'emporte, et les 25 coups s'achevent.... On fait maintenant
l'inverse: B est charge secretement de faire frapper 13 coups; A est
charge secretement de l'arreter a 7; A l'emporte encore et le
chiffre 7 ne peut etre depasse.")]
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]