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."

A research on similar lines by S. R. Steinmetz[69] in Holland shows that
the average number of children in the lowest class families is 5.44.
People in industry or small trade, skilled mechanics and professors of
theology have five children to the family; in other classes the number
is as