THE 



POPULAR SCIENCE 



MONTHLY. 



APRIL, 1910 



LAWS OF DIMINISHING ENVIKONMENTAL INFLUENCE 



By Dr. FREDERICK ADAMS WOODS 



MASSACHUSETTS INSTITUTE OF TECHNOLOGY 



IT is a widely entertained belief, especially among reformers, philan- 

 thropists and many educators, that the force of environment is 

 very great. This view may be the result of vague personal impressions, 

 natural hope, kindliness of heart or perhaps at times professional and 

 selfish interests. But do the facts of science support the expectant 

 hope? Something is needed beyond dogmatic statements and wordy 

 essays. 



Experimentally and statistically there is not a grain of proof that 

 ordinarily environment can alter the salient mental and moral traits 

 in any measurable degree from what they were predetermined to be 

 through innate influences. Yet there is naturally a feeling that envi- 

 ronment must count for something, and from experimental zoology 

 we know that in many ways its influence is very great. Surely the 

 institutions, discoveries and inventions of civilization form an envi- 

 ronment, the value of which from one point of view, is difficult to 

 overestimate. How then can we bring relative order and laws out 

 of the conflicting testimony? It is the purpose of this article by 

 treating the subject from the comparative standpoint, and after a 

 new method, to attempt to harmonize the diversified facts of inheritance 

 and modification. 



To distinguish between the relative importance of heredity and en- 

 vironment is not a mere academic question, but a practical one to be 

 answered separately for each biological trait and always with an eye 

 to comparative and proportionate influence. To say that both forces 

 are important is to voice a platitude. To say that they are of equal 

 importance is, in my opinion, to express a falsehood. To say that we 

 can not unravel their interrelations is to turn our back, in a weak- 



VOL. LXXVI. —22. 



