CHAPTER VII 

 THE CAUSES OF THE DECLINING BIRTH RATE 



"Of the thirty-eight physicians [in New York] who were willing to 

 discuss the matter I asked: 'What do you find to be the ideal American 

 family? ' Thirty said, ' Two children, a boy and a girl ; ' Six said ' One 

 child.' One said, ' Having a family is not an American ideal; ' and one 

 said, 'Five or six.'" L. K. Commander, The American Idea. 



"I wouldn't have another for the world. I had Lucy when I was 

 first married and didn't know any better." Mrs. C. of New York. 



THE practical problem of remedying the evils of the present 

 differential birth rate requires for its solution a knowledge of the 

 causes by which this condition is brought about. Spencer attrib- 

 uted the low birth rate among the intellectual classes to the 

 "antagonism between Genesis and Individuation," the utiliza- 

 tion of vital energy in cerebration being supposed to diminish, by 

 a sort of compensating loss, the power of producing offspring. He 

 admits that " special proofs that in man great cerebral expendi- 

 ture diminishes or destroys generative power, are difficult to 

 obtain." Certainly cases enough might be adduced in which men 

 of high intellectual power have shown no lack of fertility, but 

 among women it seems more probable that intense and continued 

 application to mental work might produce at least a partial 

 sterility. A half century ago large families among the intellectual 

 classes were not uncommon. The rapid decline of the birth rate 

 within a couple of generations can scarcely depend upon any deep 

 seated organic changes occurring in the human species. Our 

 changed modes of life with their greater drafts upon nervous 

 energy may have had a certain effect in reducing the natural 

 fecundity of the female sex, but it is questionable if much of the 

 decline in the birth rate can be attributed to this cause. 



In interpreting statistics concerning the number of births per 

 thousand of the population, we must consider the effect of de- 



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