Male births | 157,755 | 189,733 | 4.464 | 2,958
Female births| 149,205 | 179,505 | 4.254 | 2,850
Masculinity | 105.73 | 105.70 | 104.9 | 103.8
--------------------------------------------------------------

In the face of these statistics it is impossible to deny that
endogamy within a great social class or an ethnic race may have some
tendency to produce an excess of male births, while exogamy in this
broad sense may diminish the masculinity. But the perpetuation of a
comparatively pure race by marriage within that race, and
consanguineous marriage in the narrower sense are different
propositions. It may easily be that the marriage of individuals of a
similar type regardless of consanguinity produces a greater excess of
male offspring. According to the percentage of first cousin marriages
among the Jews as given by Mulhall,[33] and allowing the average
number of children to a marriage, there would be only 3100 children of
such marriages among the Jewish births in Prussia, and in order that
these might raise the masculinity of Jewish births even from 106 to
107 the 3100 births would have to have a masculinity of 200. Among
Protestants, or especially among Catholics where the percentage of
cousin marriage is much smaller, it seems hardly reasonable that the
general masculinity would be appreciably affected. A much better case
can be made for similarity or difference of race as the cause of the
variation. The difference between Catholic and Protestant is, roughly
speaking, the difference between the brachycephalic brunette Alpine
race and the dolichocephalic blonde Baltic race. So that a mixed
marriage in Germany would almost always mean the crossing of two
distinct types.

[Footnote 33: _Dictionary of Statistics, op. cit._, p. 383.]