WiLLCox: Differential Fecundity 



145 



from the native and from the foreign- 

 born. After this correction has been 

 made, the fecmidity of the foreign-born 

 was found to be a Httle more than twice 

 that of the native. The birth rate 

 varied with the place of birth of the 

 mother, the lowest rate being found 

 when the Massachusetts wife was born 

 in some other New England state; the 

 highest rate when the Massachusetts 

 wife was born in Portugal, the latter 

 rate being more than four times the 

 former. When all women over 50 years 

 of age and all younger unmarried women 

 were excluded, the birth rate of foreign- 

 born wives was found to- be greater than 

 that of the native by about three-fourths. 

 Another study of the fecundity of 

 married women in New Hampshire, 

 comparing native and foreign-born wives, 

 and introducing a classification by age, 

 added the interesting result that, while 

 the birth rate of foreign-born wives at 

 all ages was twice that of native wives, 

 this was a resultant or average of differ- 

 ences which grew steadily greater with 

 the age of the classes compared. The 

 birth rate of foreign-born wives at ages 

 under 20 exceeded that of native wives 

 by less than one-fourth, but at ages 25 

 to 34 it was more than double and at 

 ages 35 to 44 was almost treble that of 

 native wives. ^ This suggests that a 

 large pare at least of the difference 

 between the fecundity of the native and 

 the immigrant stock in New Hamp- 

 shire is due to psychological rather than 

 physiological causes, or causes which 

 express themselves in the voluntary 

 choice of small families rather than in 

 sterility. An attempt to estimate the 

 comparative fecundity in 1900 of native 

 and foreign-born women in the United 

 States, including wives and spinsters 

 and with no allowance for differences in 

 age distribution, indicated that the 

 fecundity of foreign-born women ex- 

 ceeded that of native women by more 

 than 50%." 



The statistics of Massachusetts, al- 

 though they were probably as good as 

 those of any state, did not and do not 

 yet afford the information needed for a 

 thorough study of the death rates, and 

 so of the difference between birth rate 

 and death rate, or natural increase, of 

 the native and foreign-born, but a 

 comparison of the existing material with 

 that furnished in Berlin, where a similar 

 problem has been studied perhaps as 

 carefully as anywhere in the world, led 

 Dr. Kuczynski to conclude that the 

 native population of Massachusetts is 

 probably dying out at a rapid rate. 



native population dying out. 



Since his articles were written, mater- 

 ial has accumulated making it possible 

 to compare the mortaHty of the native 

 and the foreign-born in 1900 in the 

 registration area of the United States, 

 which embraced two-fifths of the popu- 

 lation of the country and much more 

 than that proportion of the foreign- 

 bom, and in 1910 in New York State.^ 

 These results show that for ages be- 

 tween 10 and 40 there is very little 

 difference between the death rates of 

 natives and of foreign-born of the same 

 sex and age, and that what differences 

 do exist are quite as often in favor of 

 the foreign-born as the native. Since 

 the fecundity of the foreign-born is at 

 least 50% greater than that of the 

 native, and the mortality is about the 

 same, the difference between them, or 

 the natural increase of the foreign-bom, 

 must be far above that of the native 

 population. 



Another classification of the popula- 

 tion has been employed in studies of 

 differential fecundity, that into the 

 urban and the rural population. Under 

 urban is included all residents of cities 

 each having at least 25,000 inhabitants, 

 all the rest of the population being 

 treated as rural. The division line of 

 25,000 is much too high, but the form 



^A. A. Young, "Birth Rate in New Hampshire," in American Statistical Assn. Quart. Pubs., 

 IX: 280 (September, 1905). 



"•Twelfth Census, Supplementary Analysis, p. 420. 



^This is the only fact brought out, I believe, for the first time in the present paper. The results 

 for New York State in 1910 will be found in my last report as consulting statistician to the New 

 York State Department of Health; the confirmatory results for about forty per cent, of the popu- 

 lation of the United States in 1900 have been computed from a ms. table kindly furnished me by 

 the Census Bureau. 



