64 



The Journal of Heredity 



Table I. — Length of Li joj Fathers and Child-mortality of Their Children in Royal and Princely 



Families, Ploetz's Data 



are closely associated with the differences 

 in longevity of the father. ^ 



Longevity is a measure of soundness 

 of physical constitution — of vitaHty and, 

 to a large extent, of inheritable vitality. 

 The table admits of but one explana- 

 tion. There is a low death-rate among 

 children who inherited sound constitu- 

 tions; there is a high death-rate among 

 children who inherited weak constitu- 

 tions ; and in the latter case this inherited 

 handicap cannot be removed by the best 

 possible environment. 



If the interpretation here given is cor- 

 rect, the conclusion is inevitable that 

 child mortality is primarily a problem of 

 eugenics, and that all other factors are 

 secondary. There is found to be no 

 warrant for the statement so often 

 repeated in one form or another, that 

 "the fundamental cau.sc of the exces- 

 sive rate of infant mortality in industrial 

 communities is poverty, inadequate 

 incomes, and low standards of living."^ 

 Royalty and its princely relatives are 

 not characterized by a low standard of 

 living and yet the child mortality among 

 them is \'er\' high —somewhere around 

 400 jjer 1000, in cases where a parent 

 died young. If poverty is responsible 

 in the one case, it must be in the other — - 

 which is absurd. Or else the logical 

 absurdity is involved of inventing one 

 cause to explain an effect today and a 

 wholly different cause to explain the 

 same effect tomorrow. This is unjusti- 

 fiable in any case, and it is particularly 

 so when the single cause that explains 

 both cases is so evident. If weak 



heredity causes high mortality in the 

 royal families, why, similarly, cannot 

 weak heredity cause high infant mor- 

 tality in the industrial communities? I 

 believe it does, and that the inadequate 

 income and low standard of living are 

 largely the consequences of inferior 

 heredity, mental as well as physical. 



The careful investigation of Mary 

 Beeton and Karl Pearson, with alto- 

 gether different material, fully confimis 

 the results of Dr. Ploetz' study, and 

 leaves no room for doubt that the mor- 

 tality among children is largely depen- 

 dent on their inheritance.* If the 

 parents have inherently weak constitu- 

 tions, or minds, no measures known to 

 science can endow their children with 

 strong physique and mentality. 



BASIS FOR SOLVING PROBLEM 



If the infant mortality problem is to 

 be solved on the basis of knowledge and 

 reason, rather than emotion and rhetoric, 

 it must be recognized that sanitation 

 and hygiene can not take the place of 

 eugenics any more than eugenics can 

 dispense with sanitation and hygiene. 

 It must be recognized that the death- 

 rate in childhood is largely selective, and 

 that the most eflectix-e way to cut it 

 down is to endow the children with 

 better constitutions. This can not be 

 done solely by any euthenic campaign; it 

 can not be done by swatting the fly, 

 abolishing the midwife, sterilizing the 

 milk, nor by any of the other panaceas 

 sometimes proposed. 



But, it may be objected, this discus- 



* And also of the mother, 

 classes. 



Dr. Ploetz presents tables for both parents, and for several social 

 es." The one reprinted in this review is the most crucial but all of them are in Rood agreement. 

 «Hibbs, Henry H., Jr. Infant MortaHty: Its Relation to Social and Industrial Conditions, 

 New York, 1916. 



* Biometrika I, p. 60. 



