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 fi