166 BEGINNINGS OF INTELLIGENCE 



We have in this modification of instincts through the 

 pleasurable or painful effects they produce the beginning of 

 intelligence. The pecking, swallowing, and avoidance of 

 certain objects are purely instinctive acts based on the 

 chick's inherited organization. After its first experiences 

 with pleasant or nasty caterpillars the chick is a different 

 creature; it has learned by experience; and henceforth its 

 acts, which at first were in a general way adaptive, become 

 more perfectly adapted to its needs as the result of its learn- 

 ing. Instinct supplied the impetus to action and in a measure 

 determined the direction of action, but intelligence refines 

 upon the instinctive behavior and effects a closer adjustment 

 to the environment. 



In lower forms associations are formed as a rule with great 

 slowness. Behavior is almost entirely instinctive, and the 

 organism can be made to deviate from its stereotyped 

 methods of action only with difficulty. It is probable that 

 in low forms where associations of only the simplest kind can 

 be established there is no association of ideas involved; 

 and in fact there is no conclusive evidence of the existence 

 of ideas even in animals quite high in the scale. Most animal 

 learning consists in forming associations between certain 

 sense experiences and certain actions which bring pleasure 

 or pain. A common way of teaching an animal a trick is to 

 try in various ways to induce it to perform the desired 

 action and then to reward it by food or some other means 

 of giving it pleasure. In this way the connection between 

 the situation and the act is reinforced, and the act follows 

 more readily when the animal is placed a second time under 

 the same conditions. 



Consider the case of a cat placed in a box which can be 

 opened by pressing down a lever or pulling a string, as in the 

 experiments of Thorndike. If the cat is hungry and food 



