We compared the Wechsler scores of individuals with twice-exceptionality (2e) and giftedness using a three-level Bayesian meta-analysis. Ninety-five effect sizes were calculated from 15 studies (n = 2,106). Results show that individuals with 2e who have learning disabilities perform lower than individuals with giftedness in Full-Scale Intelligence…

Normative comparisons are an integral component of neuropsychological test interpretation and provide the basis for an inference of abnormal function and impairment. In order to remedy a deficit of normative standards for a large number of neuropsychology tests, Mitrushina, Boone, Razani, and D'Elia (2005) used the meta-analysis of studies that…

IQ test scores should be corrected for high stakes decisions that employ these assessments, including capital offense cases. If scores are not corrected, then diagnostic standards must change with each generation. Arguments against corrections, based on standards of practice, information present and absent in test manuals, and related issues,…

A meta-analysis of the stability of low IQ (IQ less than 80) was performed on IQ tests that have been commonly used--tests that were derived by D. Wechsler (1949, 1955, 1974, 1981, 1991, 1997) and those based on the Binet scales (L. M. Terman, 1960; L. M. Terman & Merrill, 1972). Weighted-mean stability coefficients of 0.77 and 0.78 were found…

This article synthesizes the experimental literature that compares the academic, cognitive, and behavioral performance of adults with reading disabilities to those of average-achieving adult readers. The central question posed by this review is to what extent and in what manner do adults with reading disabilities differ from adults without reading…

Although attention has been given to the intellectual functioning of children with attention-deficit/hyperactivity disorder (ADHD) relative to their non-ADHD peers, few studies have examined intellectual functioning in adults with ADHD. The purpose of the current investigation was to examine differences in intellectual ability between adults with…