The Mental Life of the Monkeys 215 
This makes the results appear less elegant and definitive but 
really increases their value for purposes of interpretation. 
The thoughtful reader will not expect from my experi- 
ments any perfectly rigorous demonstration of either the 
presence or the absence of imitation of human acts as a 
means of learning. | The general trend of the evidence, it 
seems to me, is decidedly towards justifying the hypothesis 
that the monkeys did not learn acts from seeing me do 
them.| 
I will first describe a sample experiment and then present 
a summary of all those made. 
On January 12th I put box Epsilon (push down) in No. 
3’s cage, the door of the box being open. I puta bit of food 
in the box. No. 3 reached in and took it. This was re- 
peated three times. I then put in a bit of food and closed the 
door. No. 3 pulled and bit the box, turned it over, fingered 
and bit at the hole where the lever was, but did not succeed 
in getting the door open. After ten minutes I took the box 
out. Later I took No. 3 out and let him sit on my knees (I 
sitting on the floor with the box in front of us). I would 
then put my hand out toward the box and when he was 
looking at it would insert my finger and depress the lever 
with as evident a movement as I could. The door, of 
course, opened, and No. 3 put his arm in and took the 
bit of food. I then put in another, closed the door and de- 
pressed the lever as before. No. 3 watched my hand pretty 
constantly, as all his experiences with me had made such 
watching profitable. After ten such trials he was put back 
in the cage and the box put in with a large piece of food in it 
and its door closed. No. 3 failed in five minutes and the 
box was taken out. He was shown fifteen times more and 
then left\to try himself. I tried him for a couple of minutes 
under just the same circumstances as existed during the 
