18U 



The Journal of Heredity 



not the case in Pittsburj^h in 1912.^ 

 A moment's consideration will show 

 that the result we obtained was to be 

 expected; for the infant deaths in a year 

 are only about 10% of the births in a 

 year, and therefore any variation in 

 the rate of infant mortality would be 

 insignificant in causing a variation in 

 the rate of first-year increase. If all 

 the deaths up to maturity could be 

 counted, we might conceivably find 

 that the mortality in the worst wards 

 was great enough to leave the best 

 wards in the lead. It is, however, 

 highly improbable that this is the case : 

 the data available do not offer any 

 information on the ix)int. 



EFFECT OF ILLITERACY 



\Vc know in a general way that the 

 ignorant and less prosperous part of 

 the community produces the most 

 children, but we rarely get figures to 

 show just how close the association of 

 these two facts is. In the Pittsburgh 

 statistics, however, we find the number 

 of illiterates in each ward stated. Now 

 if many of the residents of a district 

 can neither read nor write, it is probably 

 safe to assume that that ]X)]nilation is 

 below the average in intelligence. 

 Grading the various wards in this way, 

 and correlating with the net increase, 

 we get a coefficient of .731. Here is a 

 very high degree of association, which 

 proves that the performance is regular — 

 the more ignorance, the more babies. 

 Advocates of birth control will i)erhaps 

 read a meaning into this. They would 

 doubtless expect likewise to find infant 

 mortality highly correlated with illiter- 

 acy, but here there is another surjjrise. 

 The coefficient is .254 ±.129— that is, 

 not significant. The infant mortality is 

 higher in some of the well-to-do and 

 supposedly intelligent wards than it is 

 in some of the illiterate factory and slum 

 districts. 



This seems to me to be the most 

 important fact which Miss Scorer's 

 data reveal. It is desirable to see the 

 exact figures in this case, and I give them 



in taljular form below. The rate for 

 infant mortality is, as stated above, 

 got by dividing the number of deaths 

 under one year in a ward \)y the numlx^r 

 of births in the same ward, both figures 

 l>eing for the year 1912. The rate of 

 illiteracy is got by dividing the total 

 number of illiterates by the total number 

 of peo]:)le 10 years of age or over in the 

 ward, both figures again being for 1912. 

 It is not clear how the cen.sus defined an 

 illiterate person — presumably children 

 were excluded, at least. Whatever the 

 standard may have been, it was the 

 same for all the wards, so that the 

 comparison of wards is fair even if the 

 standard leaves something to be desired. 

 The figures follow: 



It seemed very desirable to know 

 whether this state of affairs existed only 

 in 1912, or was jjermanent, so the infant 

 mortality rates of the various wards in 

 1913. 1914, and 1915 were secured from 

 tlie Board of Health, and correlated 

 with the illiteracy of the wards for 1912. 

 In 1913 the correlation was .55S±.042, 

 a much better showing for the more 



' In only one case was I able to determine whether or not 1912 was an exceptional year for 

 Pittslnirgh's vital statistics. The infant mortality for both 1912 and 1911 was given; correlating 

 the ranks of the wards for this I found an as.sociation of .94, which shows that there was little 

 change in the jjosition of the various wards between those two years. 



