l:;s JOI IX B. WATSON 



urged in the conduct of the work was the failure to carry out con- 

 trol tests without punishment in each of the three sets of experiments. 



Mammals. Hamilton's (n) paper voices a protest against 

 the detailed and narrow experimental studies in behavior. His 

 interest is not centered in the acquisition of definite habits, but 

 rather in the reaction tendencies displayed by the animal when 

 face to face with a situation for which it has no appropriate 

 instinct, no opportunity for imitation, and no rational equip- 

 ment. He states his problem as follows: "What, if any, are 

 the qualitative differences of reaction tendency that account for 

 the fact that some mammals learn slowly, and with many errors, 

 to meet situations which their fellows of superior age or race 

 learn to meet quickly and with few errors? " In order to gain 

 insight into the different reaction tendencies of his subjects, he 

 gives them a problem in which it is required to obtain exit from 

 a room containing five doors. One of the doors is for entrance 

 only. Each of the remaining four doors may give exit but only 

 one gives exit in any given trial. The subject has to find which 

 door gives exit. He must push against it : if he finds it locked 

 he must try another. It' will be seen at once that the type of 

 problem is quite new. 



The subjects chosen were human beings, monkeys, dogs, cats 

 and horses, of different ages. From the varying behavior of 

 these subjects he succeeds in isolating what he calls various 

 types of reaction : 



Type A: "The reaction must include a single, definite effort 

 to open each of the three inferentially possible doors, and must 

 not include an effort to open the inferentially impossible door." 

 (The impossible door varied from trial to trial). This is the 

 rational inference type: apparent only in the eight normal adult 

 subjects. 



Type B : This reaction involves trying all four doors but once 

 each and in an irregular order: The unmodified searching ten- 

 dency. It is exhibited by one defective and by all of the animals 

 in the following order with respect to frequency of its display: 

 monkeys, dogs, cats, horses. 



Type C: Striking once, each of the four doors in succession, 

 starting either left or right. (This can occur only when either 

 door i or door 4 is locked). The tendency to adopt stereotyped 

 modes of searching: especially exhibited by monkeys. 



