This study tested the role of visual processing speed and IQ in reading with 124 children either with or without reading disability. Results indicated that processing speed explains a significant amount of variance in reading comprehension, as does IQ. Path analyses indicated that the effect of IQ on reading is partially mediated by decoding in…

A sample of 133 Spanish children (ages 8 to 13) was classified by IQ and reading level and given a lexical processing task. The study found that IQ did not explain differences between learning-disabled (LD) or nondisabled (NLD) children in lexical processing. Lexical and sublexical parameters had a greater influence on LD students than NLD…

Comparisons of Wechsler Intelligence Scale for Children-Revised scores, for 24 children with learning disabilities demonstrating a low verbal, high performance intelligence quotient (IQ) discrepancy and 33 slow learning children having uniformly low verbal and performance IQs, revealed few cognitive differences beyond the Performance Scale…

This article argues for the adoption of a 2-step procedure in diagnosing dyslexia: first, identify students with word list reading standard scores below 90, and then identify students with a reading score at least 10 points lower than expected from the full scale intelligence quotient. (JDD)

Word recognition data from identical and fraternal twins and siblings (N=172) indicated that the phonological coding deficit of children with reading disabilities was highly heritable. Orthographic coding was not significantly heritable. Poor readers with low IQs were superior to similar reading but average IQ readers in phonological coding.…

Use of the discrepancy approach in defining learning disabilities is challenged, as intelligence tests do not measure potential, are not independent from what is measured by achievement tests, and are not powerful predictors of low reading performance. Use of intelligence tests in analysis, identification, and definition of learning disabilities…

In commenting on Linda Siegel's argument (in EC221505) that Intelligence Quotient is not causally related to reading difficulties, this paper argues that Intelligence Quotient is relevant to the definition of reading disabilities but that present knowledge may not justify its use in the selection of children for special services. (JDD)

This investigation (with 30 normal students and 30 students with reading disabilities, ages 7-15) examined the relationship between intelligence and phonological coding when ability was defined according to the Planning, Attention, Simultaneous, Successive (PASS) cognitive processing model. Findings indicate that phonological problems may not be…

This response to a paper by Linda Siegel (EC221505) discusses research on the relationship between social skills and Intelligence Quotient or academic performance. The research indicates that it is erroneous to assume that Intelligence Quotient or academic achievement account for the social problems of children with learning disabilities. (JDD)

In this commentary on Linda Siegel's paper (EC221505), it is argued that a minimum level of general ability is needed for successful reading performance. Above this threshold other kinds of intelligence are required and more important is the contribution of verbal efficiency, which is predicated on the covariance of phonology, morphology, and…

Results of the comparison of metacomponential functioning and knowledge acquisition of adults with either mild mental retardation or learning disabilities found that (1) knowledge base is the best predictor of metacomponential skill, (2) metacomponential orchestration differentiates the two groups, and (3) IQ mediates metacognition, but does not…

This study, with 93 third grade poor readers, 54 fifth grade poor readers (with and without reading/IQ discrepancies), and 147 nondisabled first graders, found poor readers significantly more impaired than the matched first graders on all measures of nonword reading thus supporting the hypothesis of a deficit in nonword reading skills not…

A 2-year study of 25 learning-disabled children (ages 8-14) found that intelligence quotient had no relationship to learning ability in a remedial program. Self-concept predicted patterns of successful achievement in spelling, arithmetic, and written language but not in visual word recognition. (Author/JDD)

This study evaluated the external validity of a measure of IQ subtest variability, the profile variability index (PVI), with a sample of 146 children referred for psychological testing. Correlation of PVIs on each intelligence test with achievement scores and indexes of discrepancy between actual and predicted scholastic achievement found…

This commentary re-examines Linda Siegel's four basic assumptions (in EC221505) inherent in the Intelligence Quotient-achievement discrepancy commonly used to define learning disability. The commentary also discusses the uses of alternative measures of intelligence and the role of Intelligence Quotient in the identification of learning-disabled…