d
which is associated with the thought of "yes" in the case of two
subjects. It is essentially the same in both: the head is lowered and
then raised. The first of the two subjects is more decidedly motor, and
his movements therefore were somewhat the more extensive. In the case of
the second subject the nod proper is followed by another which is
somewhat less extensive.

[Illustration: FIG. 14.]

[Illustration: FIG. 15.]

A number of other experiments were carried out which corresponded with
the color-selecting tests made upon Hans. (Page 78.) Five sheets of
white paper, 1/2 meter long and 1/4 meter wide, were arranged in a
series upon the floor, 1/4 meter apart. A dot marked the middle of each.
The experimenter stood at a distance of 7-1/2 meters and directly
opposite the middle sheet. At about 1/2 meter to the right or left of
him stood the subject who took the part of the "horse". The problem of
the experimenter was to indicate to the "horse" a certain one of the
five sheets, but without the use of word or gesture. I at first
undertook the role of "horse", whereas the others consecutively played
the part of questioner. All of them looked fixedly at the sheet which
they had in mind. Besides, it usually happened that they would turn at
least their heads, and often their bodies, more or less in the direction
of the particular sheet--and this without purpose or knowledge on their
part, but purely as a result of concentration upon the sheet they wished
me to point out. One of the experimenters remarked, quite casually,
that he had noted that I always made a better judgment, the more
intently he thought of the sheet. Others often admitted that, when I had
made an error, they had not imagined the sheet vividly, or had been
debating whether or not to decide to think of the neighboring sheet--the
one I had designated. This indecision could be noticed by the direction
of the eyes. But the following table shows how uniform, on the whole,
was the behavior of the various persons when under the guidance of the
same impulse. The number of tests was 200 in each case. All errors were
of the same character. Neighboring sheets were mistaken for each other,
and the errors were never of more than one position to either side.
Their number can easily be obtained by subtracting the percentage of
correct inferences from the total, 100%.

Experimenter: v. A. B. C. Mrs. v. H. K. Miss v. L.
Correct inferences: 88% 8