The Mental Life of Monkeys and Apes | Page 9

the apparatus. But on April 14 he was
so hungry that he was finally lured in by the use of food. He cautiously
approached the boxes and attempted to climb through on the sides

instead of walking on the floor. It was perfectly evident that he had an
instinctive or an acquired fear of the white surfaces. As the matter was
of prime importance for the success of my work, I inquired of Doctor
Hamilton, and of the men in charge of the cages, for any incident which
might account for this peculiar behavior, and I learned that some three
months earlier, while the animal cages were being whitewashed, Skirrl
had jumped at one of the laborers who was applying a brush to the
framework of one of the cages and had shaken some lime into his eyes.
He was greatly frightened and enraged. Evidently he experienced
extreme discomfort, if not acute pain, and there resulted an association
with whiteness which was quite sufficient to cause him to avoid the
freshly painted apparatus.
Having obtained an adequate explanation of this monkey's peculiar
behavior, I proceeded with my efforts to induce him to work smoothly
and rapidly, and on April 15, by covering the floor with sawdust, I so
diminished the influence of the whiteness as to render the preliminary
training fairly satisfactory. At the end of two more days everything was
going so well that it seemed desirable to begin the regular experiment.
On the morning of April 19, Skirrl was introduced to the apparatus and
given his first series of ten trials on problem 1. This problem demanded
the selection of the first door at the left in any group of open doors. The
procedure was as previously described in that the experimenter raised
the entrance doors of a certain group of boxes, admitted the animal to
the reaction-chamber, punished incorrect choices by confining the
animal for thirty seconds, and rewarded correct choices by raising the
exit door and thus permitting escape and the obtaining of food. The
trials were given in rapid succession, and the total time required for this
first series of ten trials was thirty-five minutes. Skirrl worked faithfully
throughout this interval and exhibited no marked discouragement.
When confined in a box he showed uneasiness and dissatisfaction by
moving about constantly, shaking the doors, and trying to raise them in
order to escape.
For the series of settings used in connection with problem 1, the reader
is referred to page 18. In the first setting, the doors numbered 1, 2, and
3, were opened. As it happened, the animal when admitted to the
reaction-chamber immediately chose box l. Having received the reward
of food, he was called back to D, and doors 8 and 9 having been raised

in preparation for the next trial, he was again admitted to the
reaction-chamber. This time he quickly chose box 9 and was confined
therein for thirty seconds. On being released, he chose after an interval
of four minutes, box 8, thus completing the trial.
As it is highly important, not only in connection with the present
description of behavior, but also for subsequent comparison of the
reactions of different types of organism in this experiment, to present
the detailed records for each trial, tables have been constructed which
offer in brief space the essential data for every trial in connection with a
given problem.
Table 1 contains the results for Skirrl in problem 1. It is constructed as
follows: the date of a series of trials appears in the first vertical column;
the numbers (and number) of the trials for the series or date appear in
column 2; the following ten columns present respectively the results of
the trials for each of the ten settings. Each number, in these results,
designates a box entered. At the extreme right of the table are three
columns which indicate, first, the number of trials in which the right
box was chosen first, column headed R; and second, the number of
trials in which at least one incorrect choice occurred, column headed W.
In the last column, the daily ratio of these first choices appears.
Taking the first line of table 1 below the explanatory headings, we note
on April 19 ten trials, numbered 1 to 10, were given to Skirrl. In trial 1,
with setting 1, he chose correctly the first time, and the record is
therefore simply 1. In trial 2, setting 2, he incorrectly chose box 9, the
first time. At his next opportunity, he chose box 8, which was the right
one. The record therefore reads 9.8. In trial 3, setting 3, he chose
incorrectly twice before finally selecting the right box. The record reads
6.7.3, and so on throughout the ten trials which constitute a series. The
summary for