The most global score yielded by intelligence tests, IQs, are supported by substantial validity evidence and have historically been central to the identification of intellectual disabilities, learning disabilities, and giftedness. This study examined the extent to which IQs measure the ability they target, psychometric "g." Data from…

Previous work has shown that malnutrition has deleterious effects on both IQ and aspects of temperament. It is hypothesized that while malnutrition bears a direct relation to IQ, aspects of temperament are also involved in a mediating role so that they produce indirect associations between malnutrition and IQ. The study examines the association of…

The linear loadings of intelligence test composite scores on a general factor ("g") have been investigated recently in factor analytic studies. Spearman's law of diminishing returns (SLODR), however, implies that the "g" loadings of test scores likely decrease in magnitude as g increases, or they are nonlinear. The purpose of…

The threshold hypothesis (TH) assumes the existence of complex relations between creative abilities and intelligence: linear associations below 120 points of IQ and weaker or lack of associations above the threshold. However, diverse results have been obtained over the last six decades--some confirmed the hypothesis and some rejected it. In this…

We examined the degree to which the conventional notion of g associated with IQ tests and general cognitive ability tests ("COG-g") relate to the general ability that underlies tests of reading, math, and writing achievement ("ACH-g"). Two large, nationally representative data sets and two independent individually-administered…

Background: Diagnostics and care for people with intellectual disabilities (ID) and psychiatric disorders need to be improved. This can be done by using assessment instruments to routinely measure the nature and severity of psychiatric symptoms. Up until now, in the Netherlands, assessment measures are seldom used in the psychiatric care for this…

The theory of triarchic intelligence posits that, in addition to the widely acknowledged analytical reasoning abilities, creative and practical abilities should be included in the assessments of intellectual capacities and identification of gifted students. To find support for such an approach, the present study examined the psychometric…

The general differentiation hypothesis states that the strength of the correlations among a set of IQ subtests varies with a given variable. Instances of the general differentiation hypothesis that have been considered in the literature include age and ability differentiation. Traditionally, the differentiation effect is attributed to the varying…

Background: Impairments in executive functions (EF) are consistently associated with attention deficit hyperactivity disorder (ADHD) and to a lesser extent, with disruptive behavior disorder (DBD), that is, oppositional defiant disorder or conduct disorder, in school-aged children. Recently, larger numbers of children with these disorders are…

Mental chronometry (MC) studies cognitive processes measured by time. It provides an absolute, ratio scale. The limitations of instrumentation and statistical analysis caused the early studies in MC to be eclipsed by the "paper-and-pencil" psychometric tests started by Binet. However, they use an age-normed, rather than a ratio scale, which…

We examined whether self-restraint in early childhood predicted individual differences in 3 executive functions (EFs; inhibiting prepotent responses, updating working memory, and shifting task sets) in late adolescence in a sample of approximately 950 twins. At ages 14, 20, 24, and 36 months, the children were shown an attractive toy and told not…

Although it is well established that preterms as a group do poorly relative to their full-term peers on tests of global cognitive functioning, the basis for this relative deficiency is less understood. The present paper examines preterm deficits in core cognitive abilities and determines their role in mediating preterm/full-term differences in IQ.…

Research on children's counterproductive test behavior supports a three-factor model for behaviors: inattentiveness, avoidance, and uncooperative mood. In this study, test behaviors measured by the Guide to the Assessment of Test Session Behaviors (GATSB) are rated on a sample of 110 Hispanic Spanish-speaking children included in the Wechsler…

National differences in murder, rape, and serious assault were examined in 113 countries in relation to national IQ, income, skin color, birth rate, life expectancy, infant mortality, and HIV/AIDS. Data were collated from the 1993-1996 International Crime Statistics published by INTERPOL. Violent crime was found to be lower in countries with…

This study investigated a measurement model of personality resilience and the contribution of personality resilience to lower achieving first grade students' academic achievement. Participants were 445 ethnically diverse children who at entrance to first grade scored below their school district median on a test of literacy. Participants were…