The etiology of a condition is distinct from the question of test bias (review, Reynolds & Kaiser, 1992). In fact, the need to research etiology emerges only after evidence that a score difference is a real one, not an artifact of bias. Authors have sometimes inferred that score differences themselves indicate genetic differences, implying that one or more groups are genetically inferior. This inference is scientifically no more defensible—and ethically much less so—than the notion that score differences demonstrate test bias.
Jensen (1969) has long argued that mental tests measure, to some extent, the intellectual factor g, found in behavioral genetics studies to have a large genetic component. In Jensen's view, group differences in mental test scores may reflect largely genetic differences in g. Nonetheless, Jensen made many qualifications to these arguments and to the differences themselves. He also posited that other factors make considerable, though lesser, contributions to intellectual development (Reynolds, Lowe, et al., 1999). Jensen's theory, if correct, may explain certain intergroup phenomena, such as differential Black and White performance on digit span measures (Ramsay & Reynolds, 1995).
Was this article helpful?