TEE INTELLIGENCE 'OF MONKEYS. 277 



thus to push or pull the bar back. It worked very easily, a pressure of 

 perhaps 15 grams being sufficient. On January 4, 1901, this box was 

 put in No. I's cage. He failed to get in in 5 minutes, though he was 

 active in trying to get in for about 4 minutes of the time and pulled 

 and pushed the bar a gi'cat deal, though up and down and out instead of 

 back. In his aimless pushings and pullings he nearly succeeded. He 

 failed in 5 minutes in a second trial also. I then opened the door of 

 the cage, sat down beside it, held out my hand, and when he came to me 

 took his right paw and with it (he being held in front of the box) 

 pushed the bar back (and pulled the door open in those cases when it 

 did not fall open of itself). He reached in and took the food and 

 went back to the top of his cage and ate it. I put him through the act 

 thus 10 times. I then let him try alone. He failed to get in. In this 

 and the two following days No. 1 was put through the act 80 times and 

 given frequent opportunities to open the box himself. He never derived 

 the slightest profit from the tuition. 



jSTo. 1 had eight such tests and No. 3 had six. Their behavior was in 

 some cases ambiguous but the verdict would surely be that they had no 

 general capacity to acquire these simple habits by seeing and feeling 

 themselves make the movements and get food thereby. 



The theoretical importance of the failure of the monkeys to learn 

 from example or from being put through movements consists in the 

 testimony it bears to their lack of a general fund of ideas. Adult 

 human beings learn to do things by getting ideas of the circumstances 

 and of the acts required and then proceeding to act upon these ideas. 

 We think of where we are going, and so go ; we have an idea of what we 

 wish to do and so do it. Earely if ever do monkeys learn in this way. 



The behavior of the monkeys apart from these specific experiments 

 seemed also to show their inability to acquire and use ideas of objects 

 or acts. In getting them so that they would let themselves be handled, 

 it was of almost no service to take them and feed them while holding 

 them or otherwise make that state pleasant for them. By far the best 

 way is to wait patiently till they do come near, then feed them; wait 

 patiently till they do take hold of your arm, then feed them. If you do 

 take them and hold them partly by force you must feed them only when 

 they are comparatively still. In short in taming them one comes uncon- 

 sciously to adopt the method of rewarding certain of their impulses 

 rather than certain conditions which might be associated in their minds 

 with ideas, had they such. 



Monkey No. 1 apparently enjoyed scratching himself. Among the 

 stimuli which served to set off this act of scratching was the irritation 

 from tobacco smoke. If anyone blew smoke in No. I's face he would 

 blink his eyes and scratch himself, principally in the back. After a 

 time he got in the habit of coming to the front of his cage when anyone 



