DECREASE OF SUPERIOR STOCKS 525 



duce the intellectual leaders who will advance science, 

 art, government, education, and social welfare generally. 

 Our civilization of a thousand or ten thousand years 

 hence will depend largely upon the relative fecundity of 

 our low grade and high grade stocks. 



The Decreasing Fertility of Superior Stocks. — 

 Until recently there had not been, at least for hundreds 

 of years, any marked tendency in most civilized countries 

 for one class to reproduce more rapidly than another. 

 For centuries the average mental endowment of the 

 European and American peoples had held its own, or 

 possibly even advanced slightly as a result of the greater 

 mortality among the undesirables. About half a century 

 ago, however, an ill-boding change began to take place. 

 The intellectually superior families are no longer repro- 

 ducing as rapidly as formerly, and their rate of reproduc- 

 tion has fallen far below that of the socially incompetent. 

 While the fecundity of feeble-minded families continues 

 undiminished, that of university graduates and others of 

 corresponding intellectual superiority has in two or three 

 generations decreased by something like one-half. The 

 tendency toward a differential birth rate is making alarm- 

 ing progress in all civilized countries, although less in 

 Italy, Germany, and Japan than in France, England, or 

 America. The situation is only in part relieved by the 

 somewhat lower mortality among the better classes. 



If the differential birth rate should continue, and es- 

 pecially if its differential character should become more 

 and more marked, it would be but a few hundreds or 

 thousands of years until the surviving stocks would be 

 those descended chiefly from the dregs of our present- 

 day population. If this should occur, no amount of 

 educational effort would prevent the decay of the leading 

 modern nations. There is reason to believe that such 

 an influence was largely accountable for the waning of 

 earlier civilizations, notably in the case of Greece and 

 Rome. 



