ividuals,--and secondly, to ascertain in how far the
psychical processes which I had noted in my own case and which I
believed to lie at bottom of these movements, were paralleled in, and
confirmed by, the introspections of others. The effort was made to make
the experimental conditions as nearly as possible like those under which
the horse had worked. The affective atmosphere which colored the
situations in which the horse took part, could not, of course, be
transferred, but this was in some respects an advantage. One person
undertook the role of questioner, another--myself--that of the horse.
The experiments fall into three groups, corresponding to the types of
the horse's reactions: 1, tests in counting and computation; 2, tests in
space reactions; 3, tests in fetching or designating objects.

In the experiments in counting and computation, the questioner, standing
at my right, thought with a high degree of concentration of some number
(usually between 1 and 10, but sometimes also as high as 100), or of
some simple problem in addition. Then I would begin to tap,--but in
human fashion with my right hand, rather than with my foot--and
continued until I believed that I had perceived a final signal. I thus
tested, all in all, twenty-five persons, of every age and sex (including
children of five and six years), differing also in nationality and
occupation. None of them was aware of the purpose of the experiments. It
could not escape them, to be sure, that they were being watched. It was
also evident to them that the things noted were certain tensions and
movements; but none of my subjects discovered what the particular
phenomena were that I was looking for. Only in a few isolated instances
did they report that they were conscious of any movements on their part.
With the exception of two persons, they all made the same involuntary
movements which were described in chapter II, the most important of
which was the sudden slight upward jerk of the head when the final
number was reached. It was at once evident that the direction of this
jerk depended upon the position which one had asked the subject to
assume at the beginning of the test, the direction changing whenever the
position was changed. Thus, if the subject stood with head bowed--the
body either being held erect or likewise bowed,--then release of tension
would be expressed physically by an upward jerk. (Occasionally the
entire trunk is slightly raised, so that it was p