Yfrkes, Modifiahility of Behavior. 



249 



interpretation of the facts, however, is contradicted by the following 

 results which comparison of the data of Tables 6 and 7 reveals. The 

 one-month males, although they showed only a slight initial prefer- 

 ence (0.2) for the black box, acquired the white-black habit more 

 quickly than did any other group of dancers. On the other hand, 

 the four-month males, while exhibiting a strong initial preference 

 (1.0) for the black box, acquired the habit much less quickly than 

 did the one-month individuals. In view of these facts it is impossible 

 to conclude that preference plays an all-important role as a condition 

 for white-black habit-formation. Evidently we must look elsewhere 

 for the factor or factors upon which the results of the plasticity ex- 

 periments depend. 



TABLE 7. 



Gejsteral Results of White-black Preference Tests for Individuals 

 Which Were Used in the Study of the Relation of Age to Modifiability 

 OF Behavior. 



The figures in the table represent the number of choices of the black 

 in preference to the white in series of ten tests each. 



* One male and two females whose ages were twelve months are included. 



It is quite conceivable that age or sex differences in the value of 

 the electrical stimulus may be responsible for the differences in rate 

 of habit-formation which appear. This possibility was tested experi- 

 mentally by an examination of (1) the relation of electric sensi- 

 tiveness to age and sex, and (2) the relation of strength of stimulus 

 to rapidity of habit-formation. Before attempting further to analyze 

 or interpret the results presented in the tables we shall examine the 

 experimental data which enable us to answer the questions, Does 

 the sensitiveness of the dancer to electric stimuli depend upon age 

 and sex, and, Does the strength of the electric stimulus influence the 

 rapidity of habit-formation ? 



