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…

This study examined the impact of a commonly adopted elementary universal social-emotional learning program, Second Step, on student social-emotional and academic outcomes following 2 years of implementation. The cluster-randomized wait-list control trial included 61 schools, 321 teachers, and 8,941 early elementary students across 2 states, with…

Understanding fraction magnitudes is foundational for later math achievement. To represent a fraction x/y, children are often taught to use "partitioning": Break the whole into y parts and shade in x parts. Past research has shown that partitioning on number lines supports children's fraction magnitude knowledge more than partitioning on…

Developmental delays in cognitive flexibility early in elementary school can potentially increase vulnerability for subsequent externalizing and internalizing psychopathology. The first goal of the current study was to identify latent subgroups of children characterized by different developmental trajectories of cognitive flexibility throughout…

We examined the developmental trajectories and cognitive predictors of first language Chinese reading, second language English reading, and mathematics skills in Hong Kong children in Grades 1-5. We used longitudinal data of 1,000 children (M[subscript age] = 7.59 years) assessed on phonological awareness, rapid naming, and morphological awareness…

Do social cognition and epistemological understanding promote elementary school children's experimentation skills? To investigate this question, 402 children (ages 8, 9, and 10) in 2nd, 3rd, and 4th grades were assessed for their experimentation skills, social cognition (advanced theory of mind [AToM]), epistemological understanding (understanding…

We examined the development of children's positive and negative attitudes toward other-gender peers over 1 year, and explored the longitudinal social consequences of holding positive or negative attitudes on the beholder of these attitudes. Participants were 206 second graders (Mage = 7.18 yrs, SD = .56, 50% girls) and 206 fourth graders…

The association between academic self-concept and achievement is assumed to be reciprocal. Typically, the association is analyzed by variants of the classical cross-lagged panel model. Results with more recently developed methodological approaches, for example, the random intercept cross-lagged panel model, its continuous-time implementation, and…

Although the literature consistently documents strong improvements in metacognitive skills over the elementary school years, relatively little is known about the mechanisms fueling these developments. One factor that is being discussed in the literature and targeted in the present approach is cue utilization. Cue utilization quantifies the degree…

In line with the reciprocal internal/external frame of reference model (RI/E model), it is well-established that secondary school students generate domain-specific ability self-concepts by comparing their own performance in a domain socially (i.e., with others' performance in this domain) and dimensionally (i.e., with their own performance in…

Representations of numerical value have been assessed by using bounded (e.g., 0-1,000) and unbounded (e.g., 0-?) number-line tasks, with considerable debate regarding whether 1 or both tasks elicit unique cognitive strategies (e.g., addition or subtraction) and require unique cognitive models. To test this, we examined how well a mixed log-linear…

Academic language has been shown to significantly contribute to success across school subjects. However, to date, there are no empirical studies addressing its development across primary school age. The present study investigated the growth of academic vocabulary and influential conditions from Grades 2 to 4 based on a newly developed and…

The link between behavior problems and low academic achievement is well established, but few studies have examined longitudinal relations between early externalizing behaviors before school entry and low academic achievement following transition to formal schooling. Early inattention has been particularly overlooked, despite strong associations…

Across all the domains of child development, we need to understand the temporal relationship between variables suspected to underpin growth; reading research is no exception. We conducted a preliminary evaluation of the direction of the relationship between children's morphological awareness, or the awareness of and ability to manipulate the…

Which occupation to pursue is one of the more consequential decisions people make and represents a key developmental task. Yet the underlying developmental processes associated with either individual or group differences in occupational choices are still not well understood. This study contributes toward filling this gap, focusing in particular on…