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 whi
h 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 conservatism and skepticism; namely, the fact
that every one, whether psychologically trained or not, acquires in the
ordinary experiences of life a certain degree of expertness in the
observation and interpretation of mental traits. The possession of this
little fund of practical working knowledge makes most people slow to
admit any one's claim to greater expertness. When the astronomer tells
us the distance to Jupiter, we accept his statement, because we
recognize that our ordinary experience affords no basis for judgment
about such matters. But every one acquires more or less facility in
distinguishing the coarser differences among people in intelligence,
and this half-knowledge naturally generates a certain amount of
resistance to the more refined method of tests.
It should be evident, however, that we need more than the ability merely
to distinguish a genius from a simpleton, just as a physician needs
something more than the ability to distinguish an athlete from a man
dying of consumption. It is necessary to have a definite and accurate
diagnosis, one which will differentiate more finely the many degrees and
qualities of intelligence. Just as in the case of physical illness, we
need to know not merely that the patient is sick, but also why he is
sick, what organs are involved, what course the illness will run, and
what physical work the patient can safely undertake, so in the case of a
retarded child, we need to know the exact degree of intellectual
deficiency, what mental functions are chiefly concerned in the defect,
whether the deficiency is due to innate endowment, to physical illness,
or to faults of education, and what lines of mental activity the child
will be able to pursue with reasonable hope of success. In the diagnosis
of a case of malnutrition, the up-to-date physician does not depend upon
general symptoms, but instead makes a blood test to determine the exact
number of red corpuscles per cubic millimeter of blood and the exact
percentage of haemoglobin. He has learned that external appearances are
often misleading. Similarly, every psychologist who is experienced in
the mental examination of school children knows that his own or the
teacher's estimate of a child's intelligence is subject to grave and
frequent error.