FIGURE 24.—­Balancing and reaching to the utmost.

FIGURE 25.—­Standing on three boxes (after stacking them) and
reaching for reward.

FIGURE 26.—­Lifting smaller box up toward banana.

FIGURE 27.—­The act of stacking the boxes.

FIGURE 28.—­Sequel to figure 27.

FIGURE 29.—­Box and pole experiment.  Pushing the second pole
into the box.

FIGURE 30.—­Pushing pole into box.

FIGURE 31.—­Enjoying the reward of success.

From my notes I quote the following comment on the results of the initial experiment:  “Despite all that has been written concerning the intelligent behavior of the orang utan, I was amazed by Julius’s behavior this morning, for it was far more deliberate and apparently reflective as well as more persistently directed toward the goal than I had anticipated.  I had looked for sporadic attempts to obtain the banana, with speedy discouragement and such fluctuations of attention as would be exhibited by a child of two to four years.  But in less than ten minutes Julius made at least ten obvious and well directed attempts to reach the food.  There were also wanderings, efforts to obtain aid from the experimenter, and varied attempts to escape from the cage.”

Before proceeding further with the description of the behavior of Julius in the box stacking test, I shall describe for contrast the behavior of a boy three years four months of age when confronted with a situation practically identical with that which the ape was given an opportunity to meet.  For the child, the banana was suspended, as previously described, from the roof of the cage.  The same two boxes were placed on the floor at considerable distances from the banana, and in addition, a light stick, about six feet long, and a piece of board, the latter by accident, were on the floor.  The child was asked to get the banana for Julius, and he eagerly and confidently volunteered to do so.

His behavior may best be described by enumeration of the several attempts made.  They include (1) placing the larger box nearly under the banana and reaching from it. (2) Standing of the larger box on end with resulting failure because the child could not stand on the sloping edges of the top of the box. (3) The larger box was turned on its side and the lighter box drawn up opposite it and stood on end.  The child then mounted the larger box and from it stepped to the top of the smaller.  But the boxes had not been placed beneath the banana, and when the child reached for it, he found himself several feet away from his prize. (4) The boxes were moved to a position nearly under the banana and another futile attempt was made to reach it without placing the smaller box on top of the larger one, the only position from which the child could readily obtain it. (5) The piece of board was placed on top of the larger box and from this height the child again reached upward. (6) The six-foot stick was taken up and an attempt was made