Evidence from a large-scale study of 11-year olds in Britain suggests that ambidextrous individuals may be disadvantaged in tests of verbal, nonverbal, reading, and mathematical skills relative to right- and left-handers, but this basic finding was not replicated in another study of younger boys in Germany. Here, we present data based on a…

This paper reviews the studies of socioeconomic and ethnic and racial differences in intelligence carried out in Russia/USSR during the late 1920s and early 1930s. In these studies the IQs of social classes and of ethnic minorities were tested. These included Tatars (a Caucasoid people), Chuvash and Altai (mixed Caucasoid-Mongoloid peoples), Evenk…

Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS) and Attention Deficit/Hyperactivity Disorder (ADHD) have partly overlapping symptoms. It can also be debated whether a third diagnostic category exists: children with a combined diagnosis. In this study an attempt was made to distinguish among the three groups on the basis of…

Background: Previous research with earlier versions of the WISC and WAIS has demonstrated that when administered to people who have intellectual disabilities, the WAIS produced higher IQ scores than the WISC. The aim of this study was to examine whether these differences still exist. A comparison of the Wechsler Adult Intelligence Scale-Third…

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 three year longitudinal study examined the effects of IQ, age of diagnosis, school socioeconomic status (SES) and participation in desegregation programs on the remediation of learning disabilities. Participants included 176 children who were diagnosed with a learning disability, 44 of whom were participants in a voluntary transfer program.…

Objective: To characterize the relationship between IQ and attention deficits in children with ADHD and to estimate the inattention-related mean influence on IQ when children are tested before stimulant drug treatment has been initiated. Method: Studies of various methodologies are reviewed. Results: Correlation studies show mostly weak…

Twenty people with suspected intellectual disability took the Reynolds Intellectual Assessment Scales (RIAS; C. R. Reynolds & R. W. Kamphaus, 1998) and the Wechsler Adult Intelligence Scale--3rd Edition (WAIS-III; D. Wechsler, 1997) to see if the 2 IQ tests produced comparable results. A t test showed that the RIAS Composite Intelligence Index…

The Fifth Edition of the Stanford-Binet Intelligence Scales (SB5; Roid, G. H. (2003). "Stanford Binet intelligence scales" (5th ed.). Itasca, IL: Riverside Publishing) is relatively new, with minimal published research on general populations and none with special populations. The present study provides information on the cognitive profiles of…

Definitions of specific language impairment (SLI), for both research and clinical purposes, often state that nonverbal IQ scores must be within normal limits. This use of nonverbal IQ has been criticized on several grounds, including lack of equivalence between tests. In the current study, a sample of 204 adolescents with and without language…

We studied the age-related differences in inspection time and multiple cognitive domains in a group of monozygotic (MZ) and dizygotic (DZ) twins aged 7 to 17 years. Data from 111 twin pairs and 19 singleton siblings were included. We found clear age-related trends towards more efficient visual information processing in older participants. There…

In 1989, Hallam Hurt, a neonatologist in Philadelphia, started recruiting poor inner-city women for a study of how cocaine use during pregnancy affects the developing fetus. Dr. Hurt enrolled women who had used cocaine while pregnant and balanced them against a control group of equally poor women who had not taken any drugs. Years later, when the…

In this meta-analysis of 75 studies on more than 3,888 children in 19 different countries, the intellectual development of children living in children's homes (orphanages) was compared with that of children living with their (foster) families. Children growing up in children's homes showed lower IQ's than did children growing up in a family…

Robert J. Sternberg often writes about a lecture-style psychology course he took as a college freshman in which he got a C. "There is a famous Sternberg in psychology," the professor told him at the time, "and it looks like there won't be another." To Mr. Sternberg, the vignette illustrates that conventional assessments do not measure all the…

Aims: To investigate cognitive abilities and adaptive skills in children and adolescents with myotonic dystrophy type 1 (DM1) and correlate the findings to the cytosine-thymine-guanine (CTG) repeat expansion size. Method: Cognitive level was assessed in 55 children and adolescents with DM1 (31 males, 24 females; mean age 12y 1mo, SD 5y 1mo; range…