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.