overcome the handicaps of homes that are lacking in material and cultural 

 resources with great difficulty; and some never do. 



A single measure of the social and the organic advantages of providing 

 children with more care and services may be seen in varying birth rates. 

 Among the vertebrates that do the least for their offspring, each female pro- 

 duces and distributes thousands, even hundreds of thousands, of eggs, and so 

 contributes to keeping the species alive — that is, she so replaces the adults. 

 Among the mammals and birds each female produces a few or only one or two 

 young at a time, and so the species maintains itself. 



Among human beings a mother bears from a \'ery few to twenty or more in 

 the course of her life. But in some types of social life it takes a dozen or more 

 children per family to keep the population constant, whereas in other types 

 an axerage of about three per family can maintain the population. Where the 

 young are well cared for, adults find many interesting things to do besides 

 bear many children — and bury most of them. Or, from another point of 

 view, where there are only a few young, the adults can furnish them the best 

 of care and preparation and still have more time for themselves to spend in 

 useful and interesting ways; at the same time each developing individual can 

 have more resources and better preparation for using the adult years in pro- 

 ductive and satisfying ways. 



In Brief 



Accompanying the ascent of plant and anim.al life from the lowest to the 

 highest forms, there is an increase in the dependence of the offspring upon 

 the parent. 



In more complex species the individual remains relatively longer dependent 

 upon the previous generation, and is in turn better equipped in development, 

 and often in reserves of food, to li\'e in a more complex en\'ironment. 



Among the mammals and to a less degree among the birds, the long de- 

 pendence of the young upon their parents is associated with a corresponding 

 behavior of parents and offspring. 



In the higher forms of life the species generally maintain themselves with 

 relatively fewer offspring. 



In advancing civilizations, as in advancing forms of life, the extent to 

 which each generation provides services and reserves for the offspring is re- 

 lated to the level of development. 



All social life rests upon the family, which first of all nurtures and protects 

 the infant. 



To be effective and cumulative, the gains of civilization have to result in 

 improved conditions for the young. 



431 



