" 1 (2nd series). Return to starting point ... Reward only for correct first
choices
" 2-8 ............. Same as on July 1 ..........
" 8 (2nd series). No punishment .............. Reward for each trial
" 8 (3rd series). Return to starting point ... Reward only for correct first
choices
" 9-10 ............ Same as for July 8 (3rd series)
" 10 (2nd series). Momentary confinement in ..... Reward for each correct choice
wrong boxes
" 12 .............. Return to starting point ..... Reward for correct first choice
" 12 (2nd series). 30 sec. confinement .......... Reward for each correct choice
" 12 (3rd series). 5 " " ............... " " " " "
" 13 .............. 30 " " ............... " " " " "
" 14-17 ........... Return to starting point ..... Reward for correct first choices
" 17 (2nd series). 60 sec. confinement .......... Reward for each correct choice
" 19 .............. 30 " " ............... " " " " "
" 20-26 ........... 10 " " ............... " " " " "
" 27-30 ........... Right box indicated by slight Reward in each right box
raising of exit door
momentarily.
No punishment
" 30 (2nd series). Return to starting point ..... Reward for correct first choices
" 31 .............. " " " " ..... " " " " "
" 31 (2nd series)
to Aug. 10 .... 10 to 60 sec. confinement .... Reward for each correct choice
Aug. 10 (2nd series). Threatened with whip ......... " " " " "
" 11 (1st series). " " " ........... " " " " "
" 11 (2nd series). 10 sec. confinement .......... " " " " "
" 12 .............. Threatened with whip ......... " " " " "
" 12 (2nd series). 10 sec. confinement .......... " " " " "
" 19 .............. 10 " " ............... " " " " "
" 19 (2nd series). Threatened with whip ......... " " " " "
With the above reactive tendencies and modifications of method in mind
we may continue our description of results. On June 9 there developed a
tendency to increase the magnitude of the original error by choosing
nearer the left end of the groups. This is odd, since one would
naturally suppose that an animal as intelligent as the orang utan would
tend to avoid the general region in which success was never obtained and
to focus attention on the right, as contrasted with the wrong end of
each group. _It obviously contradicts the law of the gradual elimination
of use less activities._ In other words, it is wholly at variance with
the principle of trial and error exhibited by many infrahuman organisms.
Julius, although making many mistakes, worked diligently and, for the
most part, fairly rapidly. The day's work proved most important because
of the change in method and also because of the appearance of
hesitation, the rejection of certain boxes, and the definite choice of
others. My notes record "this is a most important day for Julius in
problem 2;" but subsequent results do not clearly justify this prophecy.
The method of choosing the first box at the left and then of moving down
the line until the right one was reached was so consistently followed
that during a number of days it was possible for me to predict almost
every choice. Indeed, to satisfy my curiosity in this matter during a
number of series I guessed in advance the box which would be chosen. The
percentages of correct guesses ranged from ninety to one hundred. June
10, for example, yielded two series for which the ratio of right to
wrong first choices was 0 to 10, and in which the method described above
was used consistently throughout.
It was inevitable that punishment by confinement and the discouragement
resulting therefrom should interfere with the regularity of work and
make it extremely difficult to obtain strictly comparable results from
series to series and from day to day. The data for this problem, as
presented in table 9, have values quite different from those for the
monkeys, chiefly because of the more variable conditions of observation.
It was occasionally noted that the disintegration of a definite method
and the disappearance of the tendency on which it depended occurred
rather suddenly. Frequently it happened that having used an inadequate
method fairly persistently on a given day, the animal would on the
following day exhibit a wholly different method. Even over night a new
method might develop. In the monkeys, although there was occasionally
something comparable with this, it was by no means so evident.