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…

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…

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…

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…

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…

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…

This study explored the relationship between verbal and nonverbal intelligence scores in students from low-income households. Researchers investigated how the verbal and nonverbal scores of these students differed both by ability level and within each grade. The Reynolds Intellectual Assessment Scale was administered to 1935 kindergarten through…

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…

Many researchers have used the standard Iowa Gambling Task (IGT) to assess decision-making in adolescence given increased risk-taking during this developmental period. Most studies are cross-sectional and do not observe behavioral trajectories over time, limiting interpretation. This longitudinal study investigated healthy adolescents' and young…

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…

The stability of callous-unemotional (CU) traits and both individual and contextual factors that influence this stability have been studied in community adolescent samples but not to great extent in adolescents who have been arrested. We estimated the developmental changes in CU traits measured over the course of 36 months (6-month intervals)…

This study investigated direct and indirect effects of executive functions on reading comprehension in adolescents (N = 87, M = 14.0 years, SD = 1.5) by testing for parallel mediation of effects of working memory, task-switching, and inhibitory control via decoding and text recall/inference. Working memory showed direct and indirect effects on…