an
equal number of eminent relatives, but grade 7 has more while grade 8
has more than grade 7, and the geniuses of grade 10 have the highest
proportion of nearer relatives of their own character. Surely it cannot
be supposed that a relative of a king in grade 8 has on the average a
much less favorable environment than a relative of a king in grade 10.
Is it not fair, then, to assume that this relative's greater endowment
in the latter case is due to heredity?

Conditions are the same, whether males or females be considered. The
royal families of Europe offer a test case because for them the
environment is nearly uniformly favorable. A study of them shows great
mental and moral differences between them, and critical evidence
indicates that these differences are largely due to differences in
heredity. Differences of opportunity do not appear to be largely
responsible for the achievements of the individuals.

But, it is sometimes objected, opportunity certainly is responsible for
the appearance of much talent that would otherwise never appear. Take
the great increase in the number of scientific men in Germany during the
last half century, for example. It can not be pretended that this is due
to an increased birth-rate of such talent; it means that the growth of
an appreciation of scientific work has produced an increased amount of
scientific talent. J. McKeen Cattell has argued this point most
carefully in his study of the families of one thousand American men of
science (_Popular Science Monthly_, May, 1915). "A Darwin born in China
in 1809," he says, "could not have become a Darwin, nor could a Lincoln
born here on the same day have become a Lincoln had there been no Civil
War. If the two infants had been exchanged there would have been no
Darwin in America and no Lincoln in England." And so he continues,
urging that in the production of scientific men, at least, education is
more important than eugenics.

This line of argument contains a great deal of obvious truth, but is
subject to a somewhat obvious objection, if it is pushed too far. It is
certainly true that the exact field in which a man's activities will
find play is largely determined by his surroundings and education. Young
men in the United States are now becoming lawyers or men of science, who
would have become ministers had they been born a century or two ago. But
this environmental influence seems to us a minor one, for the man who is
highly gifted in