310 HEREDITY AND ENVIRONMENT 



A. RELATIVE IMPORTANCE OF HEREDITY 

 AND ENVIRONMENT 



The distinction between these two factors of 

 development is generally recognized and the 

 question of the relative importance of the two 

 has been discussed for ages. Which is the 

 more important, constitution or environment? 

 What characteristics are due to nature and 

 what to nurture? To what extent is man the 

 creature of heredity, to what extent the pro- 

 duct of education? The old question "Which 

 of you by taking thought can add one cubit 

 to his stature," is a vital question to-day. To 

 what extent may nature be modified by nur- 

 ture? To what extent may education make up 

 for deficiencies of birth? 



1. Formerly very great emphasis was 

 placed upon influences of environment in 

 phylogeny and ontogeny. From the earliest 

 times it has been believed that species might 

 be transmuted by environmental changes and 

 that even life itself might arise from lifeless 

 matter through the influence of favorable ex- 

 trinsic conditions. If environment could exert 



