Such consideration is made difficult by the inadequate vital statistics of the United States (which ranks with Turkey and China in this respect); but there is no doubt that the birth-rate as a whole is low, as compared with that of other countries; although as a whole it is not dangerously low and there is, of course, no necessary evil in a low birth-rate, of itself, if the quality be satisfactory. The U. S. Census tabulation for 1915 gives the following comparison of the number of babies born alive each year, per 1,000 population, in various countries:
| Russia in Europe (1909) | 44.0 |
| Japan (1911) | 34.1 |
| Italy (1913) | 31.7 |
| Austria (1912) | 31.3 |
| Spain (1913) | 30.4 |
| Austria (1913) | 28.3 |
| German Empire (1912) | 28.3 |
| Holland (1913) | 28.1 |
| Denmark (1913) | 25.6 |
| Norway (1913) | 25.3 |
| United States (registration area only, 1915) | 24.9 |
| England and Wales (1913) | 24.1 |
| Sweden (1912) | 23.8 |
| Switzerland (1913) | 23.1 |
| Belgium (1912) | 22.6 |
| France (1912) | 19.0 |
The United States birth-rate may, on its face, appear high enough; but its face does not show that this height is due largely to the fecundity of immigrant women. Statistics to prove this are given in Chapter XIII, but may be supplemented here by some figures from Pittsburgh.
Ward 7, in that city, contains the homes of many well-to-do, and contains more representatives of the old American stock than any other ward in the city, having 56.4% of residents who are native born of native parents while the majority of the residents in nearly all the other wards in the city are either themselves foreign-born, or the offspring of foreign-born parents.
Ward 7 has the lowest birth-rate and the lowest rate of net increase of any ward in the city.
With this may be contrasted the sixth ward, which runs along the south bank of the Allegheny river. It is one of the great factory districts of the city, but also contains a large number of homes. Nearly 3,000 of its 14,817 males of voting age are illiterate. Its death-rate is the highest in the city. Almost nine-tenths of its residents are either foreigners or the children of foreigners. Its birth-rate is three times that of the seventh ward.
Taking into account all the wards of the city, it is found that the birth-rate rises as one considers the wards which are marked by a large foreign population, illiteracy, poverty and a high death-rate. On the other hand, the birth-rate falls as one passes to the wards that have most native-born residents, most education, most prosperity—and, to some extent, education and prosperity denote efficiency and eugenic value. For 27 wards there is a high negative correlation (-.673), between birth-rate and percentage of native-born of native parents in the population. The correlation between illiteracy and net increase[66] is +.731.
The net increase of Pittsburgh's population, therefore, is greatest where the percentage of foreign-born and of illiterates is greatest.
The significance of such figures in natural selection must be evident. Pittsburgh, like probably all large cities in civilized countries, breeds from the bottom. The lower a class is in the scale of intelligence, the greater is its reproductive contribution. Recalling that intelligence is inherited, that like begets like in this respect, one can hardly feel encouraged over the quality of the population of Pittsburgh, a few generations hence.