IQ: R.I.P.

In the early decades of this century, "IQ," as score and concept, not only satisfied psychology's need for metrical respectability, but it caught the public's fancy and rapidly became a household word. Reified in many popular tests, it has withstood onslaughts from factor analysis, from concerned social scientists, from judicial fiat, and from scientific knowledge about mental abilities, brain functions, and neuropathology. In neuropsychological practice its use--and that of any scores representing sums or averages of disparate data obtained from tests of brain functions and mental abilities--can obscure specific facets of a subject's neuropsychological status or misrepresent it generally. This 70-year-old concept has outlived its usefulness. Neuropsychology needs to seek more appropriate alternatives to the IQ for describing and conceptualizing mental functioning.