"It must not be supposed that a high rate of infant mortality, which almost invariably accompanies a high birth-rate, either in London or elsewhere, goes far toward counteracting the effects of the differential birth-rate. Where infant mortality is highest the average number of children above the age of two for each married woman is highest also, and although the chances of death at all ages are greater among the inhabitants of the poorer quarters, their rate of natural increase remains considerably higher than that of the inhabitants of the richer.
"From the detailed study of the figures made by Newsholme and Stevenson, conclusions essentially the same as those of Heron can be drawn.... Their first step was to divide the London boroughs into six groups according to the average number of domestic servants for 100 families in each. This is probably as good a measure of prosperity as any other. They then determined the total birth-rate of the population in each group, and arrived at the following figures:
| Group | ||
|---|---|---|
| I. 10 | domestic servants for 100 families | 34.97 |
| II. 10-20 | 38.32 | |
| III. 20-30 | 25.99 | |
| IV. 30-40 | 25.83 | |
| V. 40-60 | 25.11 | |
| VI. Over 60 | 18.24 |
"In order to find out how far the differences shown by these figures are due to differences in the percentage of women who marry in each group and the age at which they marry, they corrected the figures in such a way as to make them represent what the birth-rates would be in each group, if the proportion of wives of each age to the whole population comprising the group was the same as it is in the whole of England and Wales. The corrected birth-rates thus obtained were as follows:
| Group | |
|---|---|
| I | 31.56 |
| II | 25.82 |
| III | 25.63 |
| IV | 25.50 |
| V | 25.56 |
| VI | 20.45 |
"It will readily be seen that the effect of the correction has been to reduce the difference between the two extreme groups by about one-third, showing that to this extent it is due to the way in which they differ as to the average age and number of the women who marry. Further, Groups II, III, IV and V have all been brought to about the same level, with a corrected birth-rate about halfway between the highest and the lowest. This shows that there is no gradual decrease in fertility associated with a gradually increasing grade of prosperity, but that three sharply divided classes may be distinguished: a very poor class with a high degree of fertility, to which about a quarter of the population of London belong, a rich class with a low degree of fertility, and a class intermediate in both respects."
"Eugenics is less directly concerned with this side of the question that with the relative rate of increase of the different classes. This may be found for the six groups in the usual way by deducting the death-rate from the birth-rate. The following figures for the rate of natural increase are then obtained:
| Group | |
|---|---|
| I | 16.56 |
| II | 13.89 |
| III | 11.43 |
| IV | 13.81 |
| V | 10.29 |
| VI | 5.79 |
"The figures show in a manner which hardly admits of any doubt that in London at any rate the inhabitants of the poorest quarters—over a million in number—are reproducing themselves at a much greater rate than the more well-to-do."