In the present research, we provide empirical evidence for the process of symbolic integration of number associations, focusing on the development of simple addition (e.g., 5 + 3 = 8), subtraction (e.g., 5 - 3 = 2), and multiplication (e.g., 5 × 3 = 15). Canadian children were assessed twice, in Grade 2 and Grade 3 (N = 244; 55% girls). All…

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…

Data from the Early Childhood Longitudinal Study (ECLS-K; N = 6,420; 67.9% White/non-Hispanic, 15% Hispanic, 13% Black/non-Hispanic, 2% Asian, 3% Native American/Alaska Native; 25% of parents' income <$25,000, 25% = $25,001 to $45,000, 29% = $45,001 to $75,000, 20% = $75,001 or greater) were used to test structural equation models in which…

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…

Following a large, diverse sample of 4,096 children in 27 schools, this study evaluated the impact of 3 aspects of peer relations, measured concurrently, on subsequent child aggressive-disruptive behavior during early elementary school: peer dislike, reciprocated friends' aggressiveness, and classroom levels of aggressive-disruptive behavior.…

How children and youth deal with academic challenges and setbacks can make a material difference to their learning and school success. Hence, it is important to investigate the factors that allow students to cope constructively. A process model focused on students' motivational resources was used to frame a study examining whether engagement in…

Child sleep and adjustment research with community samples is on the rise with a recognized need of explicating this association. We examined reciprocal relations between children's sleep and their internalizing and externalizing symptoms using 3 waves of data spanning 5 years. Participants included 176 children at Time 1 (M = 8.68 years; 69%…

Three complementary models of how peer relationship problems (exclusion and victimization) and aggressive behaviors relate to prospective levels of internalizing problems are examined. The additive risks model proposes that peer problems and aggression cumulatively increase risks for internalizing problems. The reciprocal risks model hypothesizes…

The study's goal was to identify the beginning of 1st grade quantitative competencies that predict mathematics achievement start point and growth through 5th grade. Measures of number, counting, and arithmetic competencies were administered in early 1st grade and used to predict mathematics achievement through 5th (n = 177), while controlling for…

The purpose of this study was to investigate the contributions of domain-general cognitive resources and different forms of arithmetic development to individual differences in pre-algebraic knowledge. Children (n = 279, mean age = 7.59 years) were assessed on 7 domain-general cognitive resources as well as arithmetic calculations and word problems…

Previous studies have found that children have difficulty solving proportional reasoning problems involving discrete units until 10 to 12 years of age, but can solve parallel problems involving continuous quantities by 6 years of age. The present studies examine where children go wrong in processing proportions that involve discrete quantities. A…