Intelligence tests and adaptive behavior scales measure vital aspects of human functioning. Assessment of each is a required component in the diagnosis or identification of intellectual disability. The present study investigated the population correlation between intelligence and adaptive behavior using psychometric meta-analysis. The main…

This study examined the exchangeability of total scores (i.e., intelligent quotients [IQs]) from three brief intelligence tests. Tests were administered to 36 children with intellectual giftedness, scored live by one set of primary examiners and later scored by a secondary examiner. For each student, six IQs were calculated, and all 216 values…

This study provides the first direct evidence of cognitive continuity for multiple specific information processing abilities from infancy and toddlerhood to pre-adolescence, and provides support for the view that infant abilities form the basis of later childhood abilities. Data from a large sample of children (N = 131) were obtained at five…

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,…

The aim of this paper is to demonstrate the dramatic consequences the application of cut-off points can have in the practice of identifying gifted individuals. The paradoxical attenuation effect describes the frequent situation in which measurements of the gifts and talents individuals possess are lower than their true values. However, in…

In behavioral research, interest is often in examining the degree to which the effect of an independent variable X on an outcome Y is mediated by an intermediary or mediator variable M. This article illustrates how generalized estimating equations (GEE) modeling can be used to estimate the indirect or mediated effect, defined as the amount by…

Mental retardation (MR) has traditionally been defined as a disorder in intellectual and adaptive functioning beginning in the developmental period. Guided by a federal definition of MR described in the Individuals with Disabilities Education Act, it is the responsibility of each of the United States to describe eligibility guidelines for special…

There is great controversy in the field of learning disabilities (LD) regarding the establishment of criteria for LD identification. The traditional approach to LD identification is to use the IQ-discrepancy. Lyon and colleagues (2001) point out the numerous problems with such an approach, including faulty assumptions about the adequacy of an IQ…

Because persons with mental retardation cannot be executed for murder, the diagnosis becomes a life and death matter. The American Association on Mental Retardation (now the American Association on Intellectual and Developmental Disabilities) and other associations agree that IQ alone is an insufficient criterion and adaptive functioning also…