te, large families are desired, and among whom there has probably
been little restraint on the birth-rate. Averaging the ratings of his
individuals from grade 1, the mentally and physically very inferior, to
grade 10, the mentally and physically very superior, he found that the
number of children produced and brought to maturity increased in a
fairly direct ratio. His figures are as follows:

BOTH SEXES (AVERAGED)

Grades for virtues 1 2 3 4 5 6 7 8 9 10
Average number of
adult
children. 1.66 2.86 2.99 2.41 3.44 3.49 3.05 3.03 3.93 3.83

Investigations of Karl Pearson and Alexander Graham Bell[72] show that
fecundity and longevity are associated. It follows that the mentally
and morally superior, who are the most fecund, are also the
longest-lived; and as this longevity is largely due to inheritance it
follows that, under natural conditions, the standard of the stratum of
society under consideration would gradually rise, in respect to
longevity, in each generation.

Such is probably one of the methods by which the human race has
gradually increased its level of desirable characters in each
generation. The desirable characters were associated with each other,
and also with fecundity. The desirable characters are still associated
with each other, but their association with fecundity is now negative.
It is in this change that eugenics finds justification for its existence
as a propaganda. Its object is to restore the positive correlation
between desirable characters and fecundity, on which the progressive
evolution of the race depends.

The bearing of natural selection on the present-day evolution of the
human race, particularly in the United States of America, must be
reviewed in a few closing paragraphs.

Selection by death may result either from inadequate food supply, or
from some other lethal factor. The former type, although something of a
bugaboo ever since the time of Malthus, has in reality relatively little
effect on the human race at present. Non-sustentative lethal selection
in man is operating chiefly through zymotic diseases and the bad hygiene
of the mentally inferior.

Reproductive selection is increasingly effective and its action is such
as to cause grave alarm both through the failure of some to marry
properly (sexual selection) and the failure of some to bear enough
children, while others bear too many (fecundal selection). It is o