REWARD AND PUNISHMENT IN HABIT FORMATION 269 



time when trained with different degrees of hunger? Why should 

 subjects of similar heredity and environment perfect a like habit 

 in so widely different lengths of time when trained with different 

 strengths of electric shock? Why should subjects with the same 

 heredity and similar environment perfect a like habit in so 

 widely different lengths of time when trained with hunger and 

 when trained with electric shock as motives? Subjects trained 

 with the most favorable condition of hunger perfected the habit 

 in very nearly one-half the number of trials that subjects trained 

 with the least favorable conditions of hunger did. Subjects 

 trained with a shock of seventy-five units perfected the habit in 

 slightly more than one-half the number of trials that subjects 

 trained with one hundred and fifty units did. Subjects trained 

 with the most favorable electric shock perfected the habit in 

 about thirty-nine trials while it took subjects trained with the 

 most favorable condition of hunger seventy-five trials. 



SOME LAWS OF LEARNING WHICH HAVE BEEN SUGGESTED 



Thorndike in his Educational Psychology gives three primary 

 laws of learning (8). 



(1) Exercise. To the situation, " a modifiable connection being made 

 by him between a situation S and a response R," man responds origi- 

 nally, other things being equal, by an increase in the strength of that con- 

 nection. To a situation, "a modifiable connection not being made by 

 him between a situation S and a response R, during a length of time T," 

 man responds originally, other things being equal, by a decrease in the 

 strength of that connection. 



Corollary to the first part of the law of exercise: 



the degree of strengthening of a connection will depend upon the 

 vigor and duration as well as the frequency of its making. 



(2) Effect. To the situation, ' 'a modifiable connection being made 

 by him between an S and an R and being accompanied or followed by 

 a satisfying state of affairs" man responds, other things being equal, 

 by an increase in the strength of that connection. To a connection 

 similar, save that an annoying state of affairs goes with or follows it, 

 man responds, other things being equal, by a decrease in the strength 

 of the connection. 



