Intelligence and Its Measurement: A Symposium--II

Discusses measurement of intelligence. Two pitfalls ought to be avoided in our thinking about the nature of intelligence. (1) We must guard against defining intelligence solely in terms of ability to pass the tests of a given intelligence scale. It should go without saying that no existing scale is capable of adequately measuring the ability to deal with all possible kinds of material on all intelligence levels. Accordingly, the validity of a new test should not be judged entirely by its correlation with existing tests, however good these may be. There must be continued search for useful outside criteria. (2) On the other hand, in our anxiety to escape the evils of a closed system we must guard against indiscriminate and ill-considered use of outside criteria. To condemn an intelligence test because it yields low correlations with success as a mill hand or street car motorman is an example of this error. Another mistake that results from over-evaluation of a single criterion is seen in the effort to embody in a given intelligence scale every kind of test which will add to its correlation with the criterion in question. This mistake is especially likely to occur if one is interested in the predictive uses of the test. The effect of this error may be to pervert grossly the test as a measure of intelligence. Let us use outside criteria, by all means, but let us use them with psychological discrimination.