The Mental Life of Monkeys and Apes eBook

This eBook from the Gutenberg Project consists of approximately 160 pages of information about The Mental Life of Monkeys and Apes.

At 10 a.m. on March 5, Julius was admitted to the large cage, and the banana was pointed out to him by the experimenter.  He immediately set about trying to get it, and worked diligently during the whole of the period of observation, which, because of the unfinished condition of some of the cages, was limited to slightly over ten minutes.  Within this period he made upward of a dozen fairly well directed attempts to obtain the food.  Chief among them were three attempts to reach the banana from different positions on the left wall of the cage (as the experimenter faced the laboratory); two attempts to reach it from different positions on the right wall; two from the large box in positions nearly under the banana; two from the large box with the aid of the experimenter’s hand; and one from the distant end of the cage(?).  There occurred, also, less definite and easily describable efforts to get at the reward.

On account of the unfinished condition of the cages, the experimenter had to remain in the large cage with Julius during the test.  This interfered with the experiment because the animal tended both to try to escape and to get the experimenter to help him with his task.  Particularly interesting is the latter sort of behavior.  After the orang utan had made two or three futile attempts to obtain the food he came to the experimenter, who was standing in one corner of the cage, took him by the hand, and led him to a point directly under the banana.  He then looked up toward the banana, grasped the experimenter’s arm, raised it, and then tried to pull himself up.  He was not allowed to get the food by climbing up on the experimenter.  A few minutes later, he again led the experimenter toward the banana, but receiving discouragement in this activity, he proceeded to devote himself to other methods.

Apart from the distractions which have been mentioned above, Julius’s attention to the food was surprisingly constant.  Whatever his position with respect to it, he seemed not for an instant to lose his motive, and to whatever part of the cage he went and whatever he did during the interval of observation was evidently guided by the strong desire to obtain the banana.  Frequently he would look directly at it for a few seconds and then try some new method of reaching it.  His gaze was deliberate and in the handling of the boxes he accurately gauged distances.  Several times he succeeded in placing the larger box almost directly under the banana, and repeatedly he located that portion of the side wall from which he could most nearly reach the coveted prize.


Orang utan, Julius, obtaining banana by piling boxes
or by using pole

FIGURE 21.—­Julius in act of setting larger box on end.

FIGURE 22.—­Placing smaller box on larger.

FIGURE 23.—­Balancing on larger box preparatory to reaching for banana.

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The Mental Life of Monkeys and Apes from Project Gutenberg. Public domain.
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