38 G. V. HAMILTON 



could not be ascribed to any change in the intrinsic reactive 

 values of the various alleys and which suddenly increased the 

 frequency with which alley No. 2 had been tried established a 

 preference for this alley which was apparent at the end of the 

 twenty-fifth trial and was maintained throughout the remainder 

 of the series. 



V 



Studies of Habit Formation by the Multiple Choice Method. — ■ 

 These studies were limited to an investigation of the value of 

 recency and frequency of advantageous reaction, and are presented 

 here to supplement the findings of the foregoing pages, which 

 include some information as to the value of these factors when 

 no element of advantage is associated with their operation. 

 Black Rat 5 and White Rats 2, 5, 6, 8 and 10 were used as 

 subjects for these experiments. On the day following a sub- 

 ject's conclusion of his 100 formal trials he was given a series 

 of habit forming trials which differed from the formal series 

 in the following features: 



1. The right alley, i.e., the only one that would afford escape 

 from the enclosure, remained the same for a given subject through- 

 out this series, so that the subject had only to learn always to 

 seek this one alley for exit in order to acquire a specifically 

 adaptive habit. 



2. In most cases the alley selected by the experimenter as 

 the right alley for the series was the one that had been entered 

 by the subject the least number of times during his 100 formal 

 trials. If, however, it appeared toward the end of the formal 

 series that an episode of repetitive (E type) reaction had inclined 

 the subject toward the alley of least frequent entrance another 

 alley was selected by the experimenter as the right one. 



3. The trials were repeated during a single session until the 

 subject failed to try any alley but the right one during six suc- 

 cessive trials. 



The records for each of the six subjects will be presented 

 separately : 



Black Rat 5 



During this subject's 100 formal trials she entered alley No. 1 

 154 times, alley No. 2 110 times, alley No. 3 89 times and alley 

 No. 4 64 times. Allev No. 1 was her first choice in 43 trials, 



