eption of moral character there
is nothing as significant for a child's future as his grade of
intelligence. Even health itself is likely to have less influence in
determining success in life. Although strength and swiftness have always
had great survival value among the lower animals, these characteristics
have long since lost their supremacy in man's struggle for existence.
For us the rule of brawn has been broken, and intelligence has become
the decisive factor in success. Schools, railroads, factories, and the
largest commercial concerns may be successfully managed by persons who
are physically weak or even sickly. One who has intelligence constantly
measures opportunities against his own strength or weakness and adjusts
himself to conditions by following those leads which promise most toward
the realization of his individual possibilities.

All classes of intellects, the weakest as well as the strongest, will
profit by the application of their talents to tasks which are consonant
with their ability. When we have learned the lessons which intelligence
tests have to teach, we shall no longer blame mentally defective workmen
for their industrial inefficiency, punish weak-minded children because
of their inability to learn, or imprison and hang mentally defective
criminals because they lacked the intelligence to appreciate the
ordinary codes of social conduct.

CHAPTER II

SOURCES OF ERROR IN JUDGING INTELLIGENCE

ARE INTELLIGENCE TESTS SUPERFLUOUS? Binet tells us that he often
encountered the criticism that intelligence tests are superfluous, and
that in going to so much trouble to devise his measuring scale he was
forcing an open door. Those who made this criticism believed that the
observant teacher or parent is able to make an offhand estimate of a
child's intelligence which is accurate enough. "It is a stupid teacher,"
said one, "who needs a psychologist to tell her which pupils are not
intelligent." Every one who uses intelligence tests meets this attitude
from time to time.

This should not be surprising or discouraging. It is only natural that
those who are unfamiliar with the methods of psychology should
occasionally question their validity or worth, just as there are many
excellent people who do not "believe in" vaccination against typhoid and
small pox, operations for appendicitis, etc.

There is an additional reason why the applications of psychology have to
overcome a good deal of conservati