Evaluating socioeconomic status bias in the WISC-R

The use of intelligence tests in making special education placement decisions for children has come under repeated scrutiny in recent years. Arguments for and against the use of IQs have centered around the issue of test bias. In California a permanent moratorium on the use of intelligence tests in placing minority group children into classes for the educable retarded has been handed down by the court. One defense proposed by advocates of mental testing has been that the tests are biased against socially and economically disadvantaged groups irrespective of race. According to Clarizio (1978), if a test predicts equally well for two groups it can not legitimately be described as biased. The purpose of this investigation was to evaluate the test bias of the Verbal IQ as measured by the Wechsler Intelligence Scale for Children-Revised in relation to predictions of academic achievement in two different socioeconomic status groups. The results indicated that Verbal IQs are not biased with respect to socioeconomic status. Derived regression equations are presented along with an analysis to inspect the statistical power of the original tests.