e coefficient of correlation between children of the same family
to be .50. That is, any individual is on the average 50% as much above
or below the average for his age and sex as his brother or sister.

"Similarities of home training might account for this, but any one
experienced in teaching will hesitate to attribute much efficacy to
such similarities. Bad spellers remain bad spellers though their
teachers change. Moreover, Dr. J. M. Rice in his exhaustive study of
spelling ability ('97) found little or no relationship between good
spelling and any one of the popular methods, and little or none between
poor spelling and foreign parentage. Cornman's more careful study of
spelling ('07) supports the view that ability to spell is little
influenced by such differences in school or home training as commonly
exist."

This is a very clear-cut case of a definite intellectual ability,
differences in which might be supposed to be due almost wholly to the
child's training, but which seem, on investigation, to be largely due to
heredity.

The problem may be examined in still greater detail. Does a man merely
inherit manual skill, let us say, or does he inherit the precise kind of
manual skill needed to make a surgeon but not the kind that would be
useful to a watchmaker? Is a man born merely with a generalized
"artistic" ability, or is it one adapted solely for, let us say, music;
or further, is it adapted solely for violin playing, not for the piano?

Galton, in his pioneer studies, sought for data on this question. In
regard to English judges, he wrote: "Do the judges often have sons who
succeed in the same career, where success would have been impossible if
they had not been gifted with the special qualities of their fathers?
Out of the 286 judges, more than _one in every nine_ of them have been
either father, son or brother to another judge, and the other high legal
relationships have been even more numerous. There can not, then, remain
a doubt but that the peculiar type of ability that is necessary to a
judge is often transmitted by descent."

Unfortunately, we can not feel quite as free from doubt on the point as
Galton did. The judicial mind, if that be the main qualification for a
judge, might be inherited, or it might be the result of training. Such a
case, standing alone, is inconclusive.

Galton similarly showed that the sons of statesmen tended to be
statesmen, and that the same was true in families of great co