1 78 . POPULAR SCIENCE MONTHLY. 



of the eighteenth century, when the decline began, and at the same 

 time I published complete statistical data for the end of the nine- 

 teenth century, when the lowest level had been reached. 



I have shown that a gradual decline had already taken place dur- 

 ing the colonial period from 6 and more children in the seventeenth 

 century to 4.5 at the end of the eighteenth; then 2 at the close of 

 the nineteenth ; data for the intervening period I had none. It seemed 

 reasonable to conjecture a gradual decline with developing civiliza- 

 tion and rapidly increasing luxury of life, but proofs were wanting. 



The Yale records fill the gap, and supply the intervening data I 

 had so far persistently but vainly searched for; they distinctly portray 

 the gradual decrease in the rate of child-birth and enable me to com- 

 plete the table, period by period, which shows the remarkable changes 

 that have taken place in family life in this country. To this the 

 highly educated portion of our population is no exception. The decline 

 is general, not confined to any one element, it is the same for college 

 graduate and laboring class, for all American-born, for highly edu- 

 cated and less highly educated, so that higher education can not be the 

 causative factor. 



This table presents a startling record for a young and vigorous 

 community, and it is but natural that we should ask for the cause 

 of this rapid decline in birth rate among all classes of the American- 

 born : where are we to seek the explanation ? It can not be in physical 

 inability, though the ravages of venereal disease are leaving their 

 traces more clearly with increasing civilization and centralization, and 

 constantly add to the number of the sterile. (This is 2.5 per cent, 

 among a simple, hard-working people in the interior of Eussia 

 (Kaluga), and in Norway, whilst 20 and 25 per cent, of marriages 

 are barren in the civilized and infected communities of the United 

 States and of France.) I find 25 and 30 per cent, of families barren 

 among the married graduates of large and centrally located colleges, 

 as low as 9 per cent, in a Princeton class with high marriage rate and 

 large families, an exceptionally healthy condition when we remember 

 that 20 per cent, of all native marriages in the entire state of Massa- 

 chusetts are childless. 



The cause for this decline in family size can not be sought in the 

 increased age for marriage, as this is delayed for all educated and 

 professional men in this country as in England by nearly three years, 

 from 27.2 to 30 for the male, and for the educated female from 24.3 to 



* This steady decrease in the number of oflFspring in college graduate fami- 

 lies IS admirably shown by Professor Thorndike in his article on ' Decrease in 

 Size of American Families' (Pop. Science Monthly, May, 1903). Unfortu- 

 nately he does not give the number of surviving children and pictures only 

 graduate families. 



