The study tested the hypotheses that boys will have an advantage learning the fractions number line and this advantage will be mediated by spatial abilities. Fractions number line and, as a contrast, fractions arithmetic performance were assessed for 342 adolescents, as was their intelligence, working memory, and various spatial abilities. Boys…

This study provides the first analyses connecting individual differences in infant attention to reading achievement through the development of executive functioning (EF) in infancy and early childhood. Five-month-old infants observed a video, and peak look duration and shift rate were video coded and assessed. At 10 months, as well as 3, 4, and…

School performance is one of the most stable and heritable psychological characteristics. Notwithstanding, monozygotic twins (MZ), who have identical genotypes, differ in school performance. These MZ differences result from non-shared environments that do not contribute to the similarity within twin pairs. Because to date few non-shared…

In this longitudinal study, we assessed 88 Hong Kong Chinese typically developing kindergarteners' Chinese character reading accuracy four times with 6-month intervals over 1.5 years with the first testing point in the fall of the second year of kindergarten (K2), during which morphological awareness, phonological awareness, orthographic…

This study extends the methodological and theoretical understanding of executive functions (EFs) in preschoolers from low- and middle-income countries (LMIC). First, the authors describe a rigorous process of adapting and evaluating six EF tasks to produce a culturally and developmentally appropriate measure of emerging EFs in a large sample of…

We investigated whether preschool children with specific language impairment (SLI) exhibit the shape bias in word learning: the bias to generalize based on shape rather than size, color, or texture in an object naming context ("This is a wek; find another wek") but not in a non-naming similarity classification context ("See this?…

Although executive functions can be improved by training, little is known about the extent to which these training-related benefits can be transferred to other tasks, or whether this transfer can be modulated by the type of training. This study investigated lifespan changes in near transfer of task-switching training to structurally similar tasks…

A number of authors have proposed models of cognitive development that explain improvements in intelligence over the course of childhood via changes in the efficiency of inhibitory processes (Anderson, 2001; Bjorklund & Harnishfeger, 1990; Dempster, 1991, 1992; Dempster & Corkill, 1999a; Harnishfeger, 1995; Harnishfeger & Bjorklund, 1993). A…

Human development is thought to evolve from the dynamic interchange of biological dispositions and environmental provisions; yet the effects of specific biological and environmental birth conditions on the trajectories of cognitive and social-emotional growth have rarely been studied. We observed 126 children at six time-points from birth to 5…