48 Animal Intelligence 



they licked themselves, and of cats 6, 2 and 4, which were 

 let out when they scratched themselves, are interesting be- 

 cause they show associations where there is no congruity 

 (no more to a cat than to a man) between the act and the 

 result. One chick, too, was thus freed whenever he pecked 

 at his feathers to dress them. He formed the association, 

 and would whirl his head round and poke it into his feathers 

 as soon as dropped in the box. There is in all these cases 

 a noticeable tendency, of the cause of which I am ignorant, 

 to diminish the act until it becomes a mere vestige of a 

 lick or scratch. After the cat gets so that it performs the 

 act soon after being put in, it begins to do it less and less 

 vigorously. The licking degenerates into a mere quick 

 turn of the head with one or two motions up and down with 

 tongue extended. Instead of a hearty scratch, the cat 

 waves its paw up and down rapidly for an instant. More- 

 over, if sometimes you do not let the cat out after this 

 feeble reaction, it does not at once repeat the movement, 

 as it would do if it depressed a thumb piece, for instance, 

 without success in getting the door open. Of the reason for 

 this difference I am again ignorant. 



Previous experience makes a difference in the quickness 

 with which the cat forms the associations. After getting 

 out of six or eight boxes by different sorts of acts the cat's 

 general tendency to claw at loose objects within the box is 

 strengthened and its tendency to squeeze through holes 

 and bite bars is weakened ; accordingly it will learn associa- 

 tions along the general line of the old more quickly. Fur- 

 ther, its tendency to pay attention to what it is doing gets 

 strengthened, and this is something which may properly 

 be called a change in degree of intelligence. A test was 

 made of the influence of experience in this latter way by 

 putting two groups of cats through I (lever), one group 



