========+===========+==============+==============+==============+==============+==============+==============+==============+==============+==============+==============+===+===+===+===+======== Date | No. of | S.1 | S.2 | S.3 | S.4 | S.5 | S.6 | S.7 | S.8 | S.9 | S.10 | R | W | R | W |Ratio of | trials | 5.6.7 | 5.6.7 | 1.2.3.4.5.6 | 1.2.3.4.5.6 | 4.5.6.7.8 | 4.5.6.7.8 | 2.3.4.5 | 2.3.4.5 | 3.4.5.6.7.8.9| 3.4.5.6.7.8.9| | | | |R to W ________|___________|______________|______________|______________|______________|______________|______________|______________|______________|______________|______________|___|___|___|___|________ August | | | | | | | | | | | | | | | | | | | | {6.5.4.6 | | | | | | | {8.7.6.5 | | | | | 19 | 1- 10 | 7.5 | 6.7 | {3.2.6.4 | 5.3.6 | {7.8.7.6 | 8 | 4.3.5.4.5.2 | 5 | 9.8.7.6.4.3 | {4.5.8.7 | 2 | 8 | 2 | 8 | 1:4.00 | | | | {3.6.1* | | {8.6.4 | | | | | {6.5.9* | | | | | | | | | | | | | | | | | | | | | | | | | {5.4.6.5 | | {8.7.6.7 | | | | | | | | | | 20 | 11- 20 | 7.6.5 | {6.5.6.5 | {4.6.5.3 | 5.3.2.4.6 | {7.5.8.8 | 8 | 5.4.3.2 | 4.5 | 8.7.6.5.4.3 | {8.7.6.8.3 | 1 | 9 | 1 | 9 | 1:9.00 | | | {7 | {2.5.1* | | {7.6.4* | | | | | {7.6.4.3.9 | | | | | | | | | | | | | | | | | | | | | | | | | {6.2.5.6 | | | | {5.3.5.4 | | | | | | | | 21 | 21- 30 | 7.6.7.6.5 | 7 | {5.3.6.5 | 2.5.5.6 | 8.6.5.4 | 8 | {3.5.3.5 | 5 | {9.8.7.6 | 8.9 | 3 | 7 | 3 | 7 | 1:2.33 | | | | {4.3.1* | | | | {4.3.2* | | {5.4.3 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 23 | 31- 40 | 7.6.5 | 6.5.7 | {6.4.3.2 | 3.2.6 | 8.7.6.4 | 8 | 5.4.5.3.2 | 5.2 | 8.7.3 | 9 | 2 | 8 | 2 | 8 | 1:4.00 | | | | {5.6.2.1 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 24 | 41- 50 | 7.6.5 | 7 | {6.2.5 | 6 | {8.7.8.7 | 8 | 5.3.2 | 5 | {9.8.7.6 | 9 | 5 | 5 | 5 | 5 | 1:1.00 | | | | {4.3.1 | | {5.7.5.4 | | | | {5.4.3 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | {8.7.3.6 | | | | | 25 | 51- 60 | 7.6.5 | 6.5.7 | 5.2.1 | 6 | 8.5.4 | 8 | 2 | 2.5 | 9.8.7.4.3 | {8.7.5.3 | 3 | 7 | 3 | 7 | 1:2.33 | | | | | | | | | | | {8.7.9* | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 26 | 61- 70 | 7.6.5 | 6.5.7 | 1 | 2.1.6 | 8.7.6.4 | 8 | 2 | 3.2.5 | 9.8.7.5.3 | {3.6.8.3 | 3 | 7 | 3 | 7 | 1:2.33 | | | | | | | | | | | {4.7.9 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | {8.6.3.3 | | | | | 27 | 71- 80 | 7.6.5 | 7 | 2.1 | 1.5.6 | 8.7.6.4 | 8 | 2 | 5 | 9.8.7.6.3 | {7.5.3.8 | 4 | 6 | 4 | 6 | 1:1.50 | | | | | | | | | | | {3.6.9* | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 28 | 81- 90 | 7.6.7.5 | 7 | 3.1 | 6 | 8.6.4 | 4.8 | 2 | 2.4.5 | 8.7.4.3 | 3.8.9 | 3 | 7 | 3 | 7 | 1:2.33 | | | | | | | | | | | | | | | | ========+===========+==============+==============+==============+==============+==============+==============+==============+==============+==============+==============+===+===+===+===+========
[Footnote *: Aided by experimenter.]
2. Sobke, Pithecus rhesus
Problem 1. First at the Left End
Sobke was somewhat afraid of the experimenter when the investigation was undertaken, and instead of willingly coming out of his cage when the door was raised, he often had to be coaxed out and lured into the apparatus with food. Whereas Skirrl was frank and rather aggressive, Sobke was stealthy in his movements, furtive, and evidently suspicious of the experimenter as well as of the apparatus. He was perfectly safe to approach, but would not permit anyone to touch him. After a few days, he began to take food from the hands of the experimenter.
Preliminary work to acquaint this monkey with the routine of the experiment was begun on April 13. As in the case of Skirrl, he was lured into the apparatus and was taught the route through the boxes to the starting point by being allowed to obtain food once each day in each of the nine boxes. The procedure was simple. The entrance door and the exit door of a particular box were raised and the animal admitted to the reaction-compartment and permitted to pass through the box whose doors stood open, take its food, and return to the starting point. Sobke very quickly learned the route perfectly and came to work steadily and rapidly. After five days of preliminary work of this sort, he was so thoroughly accustomed to the apparatus that it was evidently desirable to begin with regular training experiments.
The first series of trials was given on April 19. Both punishment and reward were employed from the first. The punishment consisted of confinement for thirty seconds in each wrong box, and the reward of a small piece of banana, usually not more than a tenth of a medium sized banana for each correct choice. The total time for the first series of trials was fourteen minutes. This indicates that Sobke worked rapidly. My notes record that he worked quickly though shyly, wasted almost no time, made few errors of choice, and waited quietly during confinement in the boxes. In this, also, he differed radically from Skirrl who was restless and always tried to escape from confinement.
Throughout the work on problem 1, punishment and reward were kept constant. Everything progressed smoothly; there were no such irregularities of behavior as appeared in the case of Skirrl, and consequently the description of results is a relatively simple matter. Sobke invariably chose the end boxes. His performance was in every way superior to that of Skirrl.
As previously, the detailed results are presented in tabular form (table 4). From this table it appears that, whereas the expected ratio of right to wrong first choices for this problem is 1 to 2.5, the actual ratio for Sobke's first series was 1 to .67. This surprisingly good showing is unquestionably due to his marked tendency to choose the end box of a group; and this tendency, in turn, may in part be the result of the preliminary training, for during that only one box was open each time. But, if the preliminary training were responsible for Sobke's tendency, it should be noted that it had very different effect upon Skirrl, and, as will be seen later, upon Julius.
The results for the ten different settings of the doors for problem 1 as they appear in table 4 are of interest for a number of reasons. In the first place, the setting 1. 2. 3 appearing twice,—at the beginning of the series and again at the end—yielded markedly different results in the two positions. For whereas no mistakes were made in the case of setting 1, there were fifty per cent of incorrect first choices for setting 10. Again, satisfactory explanation is impossible. It is conceivable that fatigue or approaching satiety may have had something to do with the failures at the end of the series, but as a rule, as is indicated by settings 1, 2, and 6, if correct choices were made at the beginning, they continued throughout the day's work.