The relation to operands (RO) principles describe the relation between operands and answers in arithmetic problems (e.g., the sum is always larger than its positive addends). Despite being a fundamental property of arithmetic, its empirical relation with arithmetic/algebraic problem solving has seldom been investigated. The current longitudinal…

This longitudinal study (three waves across a school year) investigated the links between children's motivations to respond without prejudice and their ethnic outgroup attitudes at the between-person level (means and changes over time) and the within-person level (time-specific fluctuations). Participants were 945 ethnic majority students…

High sleep quality has been associated with beneficial outcomes across the life span. Intensive longitudinal studies suggest that these beneficial effects can also be observed on a day-to-day level. However, the dynamic interplay between subjective sleep quality and affective well-being in children's daily life has only rarely been investigated.…

The present study tests two predictions stemming from the hypothesis that a source of difficulty with rational numbers is interference from whole number magnitude knowledge. First, inhibitory control should be an independent predictor of fraction understanding, even after controlling for working memory. Second, if the source of interference is…

High-quality early childcare and education (ECE) has demonstrated long-term associations with positive educational and life outcomes and can be particularly impactful for children from low-income backgrounds. This study extends the literature on the long-term associations between high-quality caregiver sensitivity and responsiveness and cognitive…

Although a number of social--cognitive and contextual correlates of defending against bullying have been identified, research on the personality traits associated with defending have yielded weak and inconsistent results. The current study provided a novel examination as to whether a tendency toward social withdrawal is associated with less…

We examined the development of numerical magnitude representations of fractions and decimals from fourth to 12th grade. In Experiment 1, we assessed the rational number magnitude knowledge of 200 Chinese fourth, fifth, sixth, eighth, and 12th graders (92 girls and 108 boys) by presenting fraction and decimal magnitude comparison tasks as well as…

Gender stereotypes about science, technology, engineering, and math (STEM) are salient for children and adolescents and contribute to achievement-related disparities and inequalities in STEM participation. However, few studies have used a longitudinal design to examine changes in gender stereotypes across a range of STEM fields. In a large,…

This work refined the complex associations between aggression (aggressive behavior and victimization) and school functioning in terms of school liking, interest, achievement, and social class climate. First, using longitudinal multilevel structural equation modeling, it was shown that aggressive behavior and victimization preceded lower school…

Prior research links need for approval (NFA; the extent to which self-worth is contingent on peer approval or disapproval) to critical developmental outcomes, but little is known about how NFA develops over time or within social contexts. To address this gap, the present study used a sophisticated analytic approach (autoregressive latent…

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…

The current study examines the extent to which associations between internalizing problems, body mass index (BMI), and language skills from early (36 months) to late childhood (fifth grade) are due to relatively stable between-child differences, time-specific correlations, or cross-lagged paths. Data from the NICHD study, Early Child Care and…

Data from 790 older school-age (M[subscript age] = 10.2 years, SD = 1.2 years) girls (N = 427) and boys from Barranquilla, Colombia (N = 449) and Montréal, Canada (N = 331) were used to replicate findings reported by Valdivia et al. (2005). This prior study revealed contextual variations in the association between two measures of social behavior,…

Growth in working memory capacity, the number of items kept active in mind, is thought to be an important aspect of childhood cognitive development. Here, we focused on participants' awareness of the contents of their working memory, or "meta-working memory," which seems important because people can put cognitive abilities to best use…

We examined developmental changes in self-esteem from late childhood to late adolescence in African American girls (N = 124), comparing skin tone groups. Girls completed a measure of self-esteem when they were in Grades 5, 7, 10, and 12, and in Grade 12 their skin tone was rated on a 3-point scale (1 = "Light," 2 = "Medium," 3…