IQ tests Stanford-Binet calculates IQ as mental age / chronological age x 100 standard IQ test Wechsler Adult Intelligence Scale uses 14 subtests (7 verbal and 7 performance) can quantify intellectual decline Wechsler Intelligence Scale for Children (WISC) used for children between ages 6 and 16 Intellectual Disability (Intellectual Developmental Disorder) Formerly known as mental retardation (DSM-IV) Onset during the developmental period that includes criterion A: intellectual and adaptive functioning deficits in conceptual, social and pratical domains Severity (on the basis of adaptive functioning, not IQ scores) mild moderate severe profound IQ scores are correlated with genetic factors school achievement