Part 10

The reactive tendencies which appeared in the work on problem 2 will now be presented in order, since I shall have to refer to them repeatedly, and the list will be more useful to the reader at this point than at the conclusion of the presentation of daily results. The following is not an exhaustive list but includes only the most important and conspicuous tendencies or methods together with the dates on which they were most apparent.

(a) May 17, choice of first box at left of group or near it, then the next in order, and so on, until the second from the right was reached. This method with irregularities and certain definite skipping was used at various times, sometimes over periods of several days, during the course of the work.

(b) June 3, preference for number 3 and number 4 developed immediately after the orang utan's illness and when he was working rather listlessly.

On June 9 and 10, the original tendency (a) reappeared and persisted for a number of series.

(c) June 14, a tendency to choose the box at or near the right end of a group, and then the one next to it. In connection with this tendency, which of course required only two choices in any given trial, interest in playing with the sawdust on the floor developed.

Again on June 21, the animal returned to the use of tendency (a).

(d) June 29, movement to box at right end of group, hesitation before it, and turning through a complete circle so that the second box from the right was faced. This, the correct box, was often promptly entered. This method, if persisted in, would obviously have yielded solution of the problem.

(e) July 5, approach to and pretense to enter the box next to the right end (right one), and then choice of some other box. This feint is peculiarly interesting, and its origin and persistence are difficult to account for.

(f) In connection with the tendency to pretend that he was going to enter the second box from the right end, Julius developed also the tendency to turn around in front of the box at the right end, starting sometimes to back into it, and then to enter, instead, the box second from the end.

(g) July, 6 and 7, a fairly definite tendency to take the one next in order or, instead, to go directly to the right box.

(h) July 10, direct first choices without approach to other boxes appeared for the first time on this date.

For this problem, it proved impossible to establish and maintain uniform conditions of experimentation. Instead, because of the failure of the animal to improve and the tendency to discouragement, both punishment and reward had to be altered from time to time, and other and more radical changes were occasionally made in the experimental procedure. Below for the sake of condensed and consecutive presentation, the most important conditions from day to day are arranged in tabular form:

CONDITIONS OF EXPERIMENT FROM DAY To DAY FOR PROBLEM 2

Date Punishment Reward

May 17 ............. 20 sec. confinement ........ Food in right box for each (Aid after 10 trials) trial

" 18 to 21 ........ 30 sec. confinement ........ Food (banana) in right box for each trial

" 22 to June 2 .... Illness, no experiments

June 3 ............... 15 sec. confinement ........ Food (banana) in right box for each trial

" 4 ............... 30 " " ............. Food (banana) in right box for each trial

" 5-10 ............ 60 " " ............. Beet, carrot and loquat, in addition to banana

" 11 .............. 10 to 30 sec. confinement .. Beet, carrot and loquat, in addition to banana

" 12 to 15 ........ 60 sec. confinement ........ Beet, carrot and loquat, in addition to banana

" 16 .............. 60 " " ............. Banana and sweet corn--former preferred

" 17 (1st series). 60 sec. confinement ........ Food (banana, as in early series)

" 17 (2nd series). No confinement in wrong box; Food only for correct first but instead, return to choices starting point by way of alleys

" 18 to 22 ........ No confinement in wrong box; Food only for correct first but instead, return to choices starting point by way of alleys

" 22 (2nd series). No punishment; allowed to Food for each trial enter boxes until right one was found " 23 .............. Return to starting point. After five wrong choices of a given box the animal was held for 60 secs. in one of the boxes and was then released by way of the exit door and rewarded when the right one was chosen

" 23 (2nd series). No punishment .............. Reward for each trial