Differentiation hypotheses concern changes in the structural organization of cognitive abilities that depend on the level of general intelligence (ability differentiation) or age (developmental differentiation). Part 1 of this article presents a review of the literature on ability and developmental differentiation effects in children, revealing…

Goals: This study examined: (a) crystallized/fluid intelligence trajectories of adolescents and adults with Down syndrome; and (b) the contribution of endogenous (health, activities of daily living--ADL) and exogenous (cognitively stimulating leisure activities) factors on adults' intelligence with age. Method: Four cohorts (N = 80) with Down…

Despite the lasting interest towards the relationship between intelligence and creativity, comparably less attention is paid to its age-related changes. Our paper considers the organization of fluid intelligence and psychometric indicators of creativity and is based on the experimental data obtained for children aged 11 (n = 99) and for young…

The goal of this study was to test nonverbal intelligence and neighborhood social capital as protective factors against future delinquency in early adolescent youth placed at risk by virtue of their involvement in childhood conduct problems. Analyzing longitudinal data from 3,028 youth (1,565 boys, 1,463 girls) in one cohort of the Longitudinal…

Children with autism often display discrepancies in their intellectual functioning, with nonverbal skills frequently being more developed than verbal. Compared to monolingual autistic children, however, much less is known about how bilingualism affects intelligence in autism. The current study examined the intelligence profiles of 146 bilingual…

Several studies have demonstrated that individual differences in processing speed fully mediate the association between age and intelligence, whereas the association between processing speed and intelligence cannot be explained by age differences. Because measures of processing speed reflect a plethora of cognitive and motivational processes, it…

Differentiation of intelligence refers to changes in the structure of intelligence that depend on individuals' level of general cognitive ability (ability differentiation hypothesis) or age (developmental differentiation hypothesis). The present article aimed to investigate ability differentiation, developmental differentiation, and their…

This study examined the identification frameworks, specific models, and assessment practices used by school psychologists to identify students with specific learning disabilities (SLD) in public schools in the United States. We surveyed school psychologist practitioners using an online survey, conducted a review of state regulations addressing…

This paper provides a meta-analytic update on the relationship between intelligence and divergent thinking (DT), as research on this topic has increased, and methods have diversified since Kim's meta-analysis in 2005. A three-level meta-analysis was used to analyze 849 correlation coefficients from 112 studies with an overall N = 34,610. The…

Background: Recent research suggested fluent processing as an explanation on why number sense contributes to simple arithmetic tasks--'Fluency hypothesis'. Aims: The current study investigates whether number sense contributes to such arithmetic tasks when other cognitive factors are controlled for (including those that mediate the link); and…

An enduring challenge in visual-spatial research has been to identify the factors contributing to individual differences in ability. This research investigated the overall, verbal, and nonverbal visual-spatial ability of 61 (34 boys) three- to five-year-olds (M[subscript age] = 57.3 months; SD = 7.9) and the following factors known to be related…

Intelligence tests and adaptive behavior scales measure vital aspects of the multidimensional nature of human functioning. Assessment of each is a required component in the diagnosis or identification of intellectual disability, and both are frequently used conjointly in the assessment and identification of other developmental disabilities. The…

Age-classes are a salient feature of modern schooling. Yet how did age-grouping come to prevail in entire school systems? And how was this form of grouping related to educational and pedagogic discussions at the time of its emergence? The article addresses these issues by looking at the historical context within which age classes came to a…

The Impostor Phenomenon (IP) is a psychological construct that causes high-achieving individuals to doubt their competence, intelligence, and sense of belonging. IP has only recently been examined among people in the music education community. The student teaching experience is a time of transition and professional identity development for…

Previous studies showed that bilinguals tend to score lower on some language tests than monolinguals in each of their languages and outperform monolinguals on some cognitive tasks. We investigated whether short-term and working memory capacities that underlie language abilities differ between sequential bilinguals and monolinguals. We tested…