Of course these illiterate foreign laborers are, from a eugenic point of view, not wholly bad. The picture should not be painted any blacker than the original. Some of these ignorant stocks, in another generation and with decent surroundings, will furnish excellent citizens.
But taken as a whole, it can hardly be supposed that the fecund stocks of Pittsburgh, with their illiteracy, squalor and tuberculosis, their high death-rates, their economic straits, are as good eugenic material as the families that are dying out in the more substantial residence section which their fathers created in the eastern part of the city.
And it can hardly be supposed that the city, and the nation, of the future, would not benefit by a change in the distribution of births, whereby more would come from the seventh ward and its like, and fewer from the sixth and its like.
Evidently, there is no difficulty about seeing this form of natural selection at work, and at work in such a way as greatly to change the character of one section of the species. For comparison, some figures are presented from European sources. In the French war budget of 1911 it appears that from 1,000 women between the ages of 15 and 50, in different districts of Paris, the number of yearly births was as follows:
| Very poor | 108 |
| Poor | 99 |
| Well-to-do | 72 |
| Very prosperous | 65 |
| Rich | 53 |
| Very rich | 35 |
Disregarding the last class altogether, it is yet evident that while the mother in a wealthy home bears two children, the mother in the slums bears four. It is evident then that in Paris at the present time reproductive selection is changing the mental and moral composition of the population at a rapid rate, which can not be very materially reduced even if it is found that the death-rate in the poorer districts is considerably greater than it is on the more fashionable boulevards.
J. Bertillon has brought together[67] in a similar way data from a number of cities, showing the following birth-rates:
| Berlin | Vienna | London | |
|---|---|---|---|
| Very poor quarters | 157 | 200 | 147 |
| Poor quarters | 129 | 164 | 140 |
| Comfortable quarters | 114 | 155 | 107 |
| Very comfortable | 96 | 153 | 107 |
| Rich | 63 | 107 | 87 |
| Very rich | 47 | 81 | 63 |
| — | — | — | |
| Average | 102 | 153 | 109 |
Obviously, in all these cases reproductive selection will soon bring about such a change in the character of the population, that a much larger part of it than at present will have the hereditary characteristics of the poorer classes and a much smaller part of it than at present the hereditary characteristics of the well-to-do classes.
David Heron and others have recently studied[68] the relation which the birth-rate in different boroughs of London bears to their social and economic conditions. Using the correlation method, they found "that in London the birth-rate per 1,000 married women, aged 15 to 54, is highest where the conditions show the greatest poverty—namely, in quarters where pawnbrokers abound, where unskilled labor is the principal source of income, where consumption is most common and most deadly, where pauperism is most rife, and, finally, where the greatest proportion of the children born die in infancy. The correlation coefficients show that the association of these evil conditions with the relative number of children born is a very close one; and if the question is put in another way, and the calculations are based on measures of prosperity instead of on measures of poverty, a high degree of correlation is found between prosperity and a low birth-rate.