352 HEREDITY AND ENVIRONMENT 



E. APPLICATIONS TO HUMAN DEVELOP- 

 MENT: EUTHENICS 



Man's environment is more extensive than 

 that of any other animal, and its influence on 

 his development is correspondingly greater. 

 In addition to chemical and physical stimuli 

 which are potent factors of development in 

 the case of all organisms, man lives in a world 

 of psychical, social and moral stimuli which 

 exert a profound influence on him. He is 

 stimulated not merely by present environment 

 but also by memories of past experiences and 

 anticipations of future ones. Through intelli- 

 gence and social cooperation he is able to con- 

 trol environment for particular ends, in a 

 manner quite impossible in other organisms. 

 On the other hand heredity is no more power- 

 ful as a factor of development in the case of 

 man than in any other organism. Conse- 

 quently the relative importance of heredity and 

 environment is not the same in the development 

 of an intelligent and social being, like man of 



