The present study longitudinally investigated proportional reasoning abilities in early elementary school before the start of its instruction. Three aims were put forward: (a) distinguishing the different developmental states in young children's understanding of missing-value proportional situations, (b) investigating how children transition…

Children start preschool with large individual differences in their early numerical abilities. Little is known about the importance of heterogeneous patterns that exist within these individual differences. A person-centered analytic approach might be helpful to unravel these patterns and the cognitive and environmental factors that are associated…

Several aspects of early language skills, including parent-report measures of vocabulary, phoneme discrimination, speech segmentation, and speed of lexical access predict later childhood language outcomes. To date, no studies have examined the long-term predictive validity of novel word learning. We examined whether individual differences in novel…

Several aspects of early language skills, including parent-report measures of vocabulary, phoneme discrimination, speech segmentation, and speed of lexical access predict later childhood language outcomes. To date, no studies have examined the long-term predictive validity of novel word learning. We examined whether individual differences in novel…

Longitudinal associations of domain-general and numerical competencies with individual differences in children's understanding of fractions were investigated. Children (n = 163) were assessed at 6 years of age on domain-general (nonverbal reasoning, language, attentive behavior, executive control, visual-spatial memory) and numerical (number…

Children experience good and bad days in their performance. Although this phenomenon is well-known to teachers, parents, and students it has not been investigated empirically. We examined whether children's working memory performance varies systematically from day to day and to which extent fluctuations at faster timescales (i.e., occasions,…

Aging-related declines occur in many different domains of cognitive function during middle and late adulthood. However, whether a global dimension underlies individual differences in changes in different domains of cognition and whether global genetic influences on cognitive changes exist is less clear. We addressed these issues by applying…

This longitudinal study examined the relationship between working memory and individual differences in mathematics. Working memory measures, comprising the phonological loop, the visuospatial sketchpad, and the central executive, were administered at the start of first grade. Mathematics achievement was assessed 4 months later (at the middle of…

At age 13, students scoring at the top 0.5% in general intelligence completed the Scholastic Assessment Test (SAT), Mathematics and Verbal subtests, and the Differential Aptitude Test (DAT) Space Relations (SR) and Mechanical Reasoning (MR) subtests. It appears that spatial ability assessments can complement contemporary talent search procedures.…

Examined, over a 10-year span, continuity in individual differences in cross-modal transfer to visually recognized shapes that had previously been felt but not seen. Found that cross-modal performance showed a left-hand advantage at 11 years. Cross-age correlations were significant when tactual exploration at 11 years was done with the left hand.…

In both 1960 and 1980, the same test of spatial-visual ability was given to national probability samples of high school seniors in the United States. The students in 1960 were participants in Project TALENT and in 1980 were participants in "High School and Beyond." In addition, a reading comprehension test was given to the 1960 students…

Examined the relationship of environmental input to cognitive growth in language, spatial operations, concepts, and associative memory in children tested four times six months apart and differing in the amount of school input received. Found that children made greater growth over periods with greater amounts of school input for language, spatial…