IT is a widely entertained belief, especially among reformers, philanthropists 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 environment 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 environment, 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 environment 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--