THE FLYNN EFFECT AND THE SHADOW OF THE PAST: MENTAL RETARDATION AND THE INDEFENSIBLE AND INDISPENSABLE ROLE OF IQ

Gains in IQ over time render test norms obsolete within a decade of the publication of an intelligence test. Obsolete norms inflate IQs and drain the pool of those eligible to be classified as having mental retardation (MR). As a result, many are missing the services they need and capital offenders are being executed who should qualify as mentally incompetent. The history of IQ gains and IQ criteria for MR pose deeper and more problematic questions: Can we salvage IQ tests as measures of intelligence; can we find an IQ criterion for MR that has external validity; can we find a mental test that measures moral culpability? All solutions involve an agonizing reappraisal of present practice.