Growing up with multiple siblings might negatively affect language development. This study examined the associations between birth order, sibling characteristics and parent-reported vocabulary size in 6163 Norwegian 8- to 36-month-old children (51.4% female). Results confirmed that birth order was negatively associated with vocabulary, yet…

This study examined gender differences in reading behavior of 2652 Danish 5th-grade students (age 10-12 years, girls 51%, 14% immigrant background) observed for 218 days in 2019/2020, using data from a popular reading app. Reading behavior was operationalized as time spent reading. Analyses of timing of reading behavior and models of day-to-day…

Prior research points to gender differences in some early language skills, but is inconclusive about the mechanisms at play, providing evidence that both infants' early input and productions may differ by gender. This study examined the linguistic input and early productions of 44 American English-learning infants (93% White) in a longitudinal…

Using data from the Early Childhood Longitudinal Study--Kindergarten Class of 2011 (n = 14,370; 51% Male; 51% White; 14% Black; 25% Hispanic; 4% Asian; and 6% Other), this study examined the cumulative, timing-specific, and enduring associations between student-teacher relationships in the United States and a broad range of student outcomes.…

Recent work suggests that the stereotype associating brilliance with men may underpin women's underrepresentation in prestigious careers, yet little is known about its development and consequences in non-Western contexts. The present research examined the onset of this stereotype and its relation to children's motivation in 5- to 7-year-old Korean…

This longitudinal study examined age- and gender-related differences in autobiographical memory about the COVID-19 pandemic lockdowns and whether the content of these memories predicted psychological adjustment over time. A sample of 247 students (M[subscript age] = 11.94, range 8-16 years, 51.4% female, 85.4% White) was recruited from public and…

With a focus on within-person effects, this study investigated mutualism among academic skills (reading, math, science) and between those skills and verbal working memory in a general population sample and groups with high or low skills from Grades 2 to 5 (2010-2016, N = 859-9040, age 6.27-13.13 years, 49% female, ethnically diverse). Mutualism…

Games are frequently used to promote math learning, yet the competitive and collaborative contexts introduced by games may exacerbate gender differences. In this study, 1st and 2nd grade children in the U.S. (ages 5-8; N = 274; 70% White, 15% Asian, 2% Black, 1% Native American, 14% mixed or other race; 17% Hispanic) played either a competitive,…

This meta-analysis synthesizes research on media use in early childhood (0-6 years), word-learning, and vocabulary size. Multi-level analyses included 266 effect sizes from 63 studies (N[subscript total] = 11,413) published between 1988-2022. Among samples with information about race/ethnicity (51%) and sex/gender (73%), most were majority…

We examined the prototype v. revisionist models of attachment stability with a five-wave, 6-year, longitudinal study of attachment security from middle childhood to adolescence in a White Western European sample (N = 157; Wave 1 M[subscript age] = 10.91, SD = 0.87; 52% female). Attachment was assessed using both questionnaire (Experiences in Close…

Three hundred and ninety-one children (195 girls; M[subscript age] = 9.56 years) attending Grades 1 and 5 completed implicit and explicit measures of math attitudes and math self-concepts. Math grades were obtained. Multilevel analyses showed that first-grade girls held a strong negative implicit attitude about math, despite no gender differences…

Distractibility is the propensity to behaviorally react to irrelevant information. Although children are more distractible the younger they are, the precise contribution of attentional and motor components to distractibility and their developmental trajectories have not been characterized yet. We used a new behavioral paradigm to identify the…

The "Developing Inclusive Youth" program is a classroom-based, individually administered video tool that depicts peer-based social and racial exclusion, combined with teacher-led discussions. A multisite randomized control trial was implemented with 983 participants (502 females; 58.5% White, 41.5% Ethnic/racial minority; M[subscript…

This study conducted two meta-analyses to synthesize the association between children's language skills and two broad-band dimensions of psychopathology: internalizing and externalizing. Pooled estimates across 139 samples (externalizing k = 105; internalizing k = 90) and 147,305 participants (age range: 2-17 years old; mean % males: 53.75; mean %…

A double-blind randomized controlled trial of n-3 long-chain polyunsaturated fatty acid (n-3 LCPUFA) supplementation or matching placebo during third trimester of pregnancy was conducted within the COPSAC[subscript 2010] mother-child cohort consisting of 736 women and their children. The objective was to determine if maternal n-3 LCPUFA pregnancy…