energy to its offspring. It follows that he thinks superior
offspring are produced by parents of advanced age, because the latter
have had more time to do work and store up energy for transmission. In
his own words:

"Educating the grandfather helps to make the grandson a superior
person.... We are, in our inheritance, exactly what our ancestors
made us by the work they performed before reproducing. Whether our
descendants are to be better or worse than we are will depend upon
the amount and kind of work we do before we produce them."

The question of the influence of parental age on the characters of the
offspring is one of great importance, for the solution of which the
necessary facts have not yet been gathered together. The data compiled
by Mr. Redfield are of value, but his interpretation of them can not be
accepted for the following reasons.

1. In the light of modern psychology, it is absurd to lump all sorts of
mental ability under one head, and to suppose that the father's exercise
of reasoning power, for example, will store up "energy" to be manifested
in the offspring in the shape of executive or artistic ability. Mental
abilities are much subdivided and are inherited separately. Mr.
Redfield's idea of the process is much too crude.

Moreover, Mr. Redfield's whole conception of the increase of
intelligence with increase of age in a parent shows a disregard of the
facts of psychology. As E. A. Doll has pointed out,[196] in criticising
Mr. Redfield's recent and extreme claim that feeble-mindedness is the
product of early marriage, it is incorrect to speak of 20-, 30-, or
40-year standards of intelligence; for recent researches in measurement
of mental development indicate that the heritable standard of
intelligence of adults increases very little beyond the age of
approximately 16 years. A person 40 years old has an additional
_experience_ of a quarter of a century, and so has a larger mental
content, but his intelligence is still nearly at the 16-year level.
Mental activity is the effect, not the cause, of mental growth or
development. Education merely turns inherent mental powers to good
account; it makes very little change in those powers themselves. To
suppose that a father can, by study, raise his innate level of
intelligence and transmit it at the new level to his son, is a naive
idea which finds no warrant in the known facts of mental development.

2. In his entire concepti