128 HEREDITY AND SOCIETY 



with changes in the price of corn or with the declaration 

 of peace or war. But, since 1875, the people have 

 learnt to restrict voluntarily the number of births in 

 married life, and the rate of reproduction has become 

 almost indefinitely more sensitive to outside influences, 

 such as those exercised by social conventions and habits 

 and legislative, especially financial, burdens. 



In all ranks of life children are a heavy expense 

 an expense which rises roughly in proportion to the 

 position of the family, and falls heavily on all save on 

 the very rich in all classes (that is, on those who have 

 more than enough to support themselves in their 

 natural position), and on the thriftless pauper, who can 

 now look with confidence to the State for the mainten- 

 ance of himself and an unlimited number of equally 

 casual offspring. In almost every household, an 

 increasing number of children means a diminution 

 in comfort and economic freedom, while, where the 

 income is small, each new child may mean actually less 

 food and clothing for the existing members of the 

 family. 



This being so, economic causes, added to other 

 motives, lead at once to restriction of the birth-rate 

 among the thrifty and far-seeing, as soon as the burden 

 of children is felt to be too severe. 



On the other hand, among the reckless and incom- 

 petent, especially when they suffer from mental defect, 

 no such restraining motives are operative, and no 

 restriction of births checks the propagation of their 

 undesirable qualities. They reproduce themselves at a 

 natural rate, and are only checked by natural causes. 

 In old days, the pressure of life was more severe. 



