Relational reasoning (RR) is a higher-order cognitive ability associated with academic performance. Most prior studies on RR-mathematics association have used a cross-sectional design. The current study aimed to examine their longitudinal relations and underlying mechanisms. A sample of 235 sixth graders (138 boys, mean age = 12.32 years, SD = .903) in Hong Kong were tested on RR (nonverbal and verbal) and mathematics achievement (numerical operations and mathematical problem-solving). One hundred and ninety-five (118 boys, mean age = 13.32 years, SD = .945) of them were re-assessed after one year on mathematics achievement and potential mediators (word problem reasoning, arithmetic fluency, and arithmetic principle understanding). Results indicated that nonverbal RR predicted numerical operations through arithmetic principle understanding, and both nonverbal and verbal RR predicted mathematical problem solving through word problem reasoning. The findings advanced the literature on RR-mathematics association and suggested directions for interventions.

Google Search is a popular tool for acquiring information online, but little is known about children's trust in search engines. Across two studies conducted in 2021-2024, 240 4- to 8-year-old children (122 boys, 118 girls; 75% White; 92% non-Hispanic) were asked whether they trusted Google and a teacher to answer questions about stable information (e.g., geographical locations) and changing information (e.g., the weather). With increasing age, children endorsed Google at higher rates and the teacher at lower rates. When asked about the Internet and an unfamiliar search engine, children endorsed Google and the Internet more often than an unfamiliar search engine. Children's intuitions about search engines changed with development, with younger children relying more on familiarity as a cue to trust.

Women are often expected to and do perform service more than men. When do these gendered expectations and behaviors develop? 127 children (aged 6-9 years, 64 girls, 63 boys, 57% white children, 43% children of color) made decisions about who should do and whether they themselves would do various classroom jobs-a child-friendly example of service. After age 9, girls were more likely to choose to do service than boys, even though children generally thought everyone should do service. Whereas parents' relevant beliefs and the gender distribution of housework did not relate to developing gender differences, parent-child conversations revealed that girls' more frequent choice to do service may be rooted in their perceived personal benefits of doing service.

Using three-wave longitudinal data of 554 Chinese youth (mean age = 13.35 years; 50% girls; T1 = July 2020, T2 = January 2021, T3 = July 2021), this study examined how youth's views of teens regarding family obligation predict their academic functioning and relationship with parents, with attention to the mediating role of youth's sense of responsibility to parents. Results showed that views of teens regarding family obligation predicted youth's greater academic delay of gratification, motivational response to academic failure, and attachment security to mother and father over time. Importantly, youth's sense of responsibility to parents mediated the longitudinal associations between views of teens and their academic and social adjustment. Taken together, the findings elucidate why and how views of teens matter for positive youth development in a culturally sensitive manner.

As adults, we do not expect ignorant agents to behave randomly or always get things wrong. Instead, we expect them to act reasonably, guided by past experiences. We test whether 4-to-6-year-olds share this intuition and use it to infer others' knowledge, or whether they rely on a simple "ignorance = error" heuristic identified in past work. Across three pre-registered experiments (n = 264 4-to-6-year-olds recruited in the US between 2018-2022; demographic data not collected), we find that 4-year-olds expect agents to draw on past experiences when acting in new situations. However, only 6-year-olds reliably use this expectation to infer others' knowledge from behavior. These findings suggest that by age 6, children use a causal model of how ignorance shapes behavior, and not just a cue-based understanding of epistemic states.

This meta-analysis examined main effects and heterogeneity in associations between popularity and academic adjustment in the U.S. and China across 41 studies. The aggregated sample included 22,151 children and adolescents (10,934 boys; 11,217 girls) from both countries, with U.S. students from various ethnic backgrounds. Results in the U.S. were characterized by developmental differences, with popularity positively linked to academic functioning only in childhood (r = 0.26) but not adolescence (r = 0.01). Conversely, popularity was consistently related to academic adjustment in China across developmental stages (overall r = 0.36). Patterns in both nations were unaffected by other demographic meta-moderators but shifted after social acceptance was partialled out. Observed cross-national differences should be interpreted with caution, and potential caveats were discussed.

This study examined the development of emotion understanding. Children (N = 296, 157 boys, 139 girls) and parents (67% White, 8% Black, 15% Hispanic, 2% Asian American, 6% Biracial, 2% "Other") recruited from Denver, Colorado were observed annually for four years starting in 2019 (beginning Mage = 2.44 years, SD = 0.26) discussing a wordless storybook featuring illustrated emoters expressing joy, sadness, fear, anger, or disgust towards a referent (e.g., dropped ice cream). Analyses revealed changes and bidirectional relations in children's and parents' emoter talk and referent talk across early childhood, as well as differences in parent and child relative emoter-referent emphasis for discrete emotions. Implications for the ontogeny and socialization of young children's emotion understanding will be discussed.

Prioritizing what information to learn based on value is a critical developmental skill. Across two studies, value-based memory was assessed predominately in White children aged 6- to 7-years-old and 9- to 10-years-old using a nationwide sample collected between 2020 and 2023. Children learned cue-target associations worth varying point values. Experiment 1 (N = 77, Nfemales = 39) demonstrated that both age groups prioritized learning high-value information across varying task demands (Cohen's d = 0.36). Experiment 2 (N = 77, Nfemales = 34) demonstrated that children also self-regulated their learning and actively selected to study and remember items based on value (Cohen's d = 0.75). However, older children were more effective at translating their value-based study choices into prioritizing recall of high-value information.

Despite the ubiquity of variation in child development within individuals, across groups, and across tasks, timescales, and contexts, dominant methods in developmental science and education research still favor group averages, short snapshots of time, and single environments. The Learning Variability Network Exchange (LEVANTE) is a framework designed to enable coordinated data collection by research teams worldwide, with the goal of measuring variability in children's learning and development. The LEVANTE measure set aims to capture variability in learning outcomes (literacy and numeracy) as well as in core cognitive and social constructs. LEVANTE will yield a large, open access longitudinal dataset for long-term research use, both creating a multidisciplinary research network and facilitating the science of learning variability.

Increasing global diversity of children and families calls for developmental sciences to incorporate the dynamic interactions of race, ethnicity, culture, and other contextual experiences. However, navigating ecological and cultural theories defies our disciplinary-based training. Promoting interdisciplinary multisector research is necessary. With parenting as a lens, I described my journey toward increasingly interdisciplinary and multisector research. Interactions among ethnicity, community, and socioeconomic status varied by developmental stage and context, resulting in revisiting conceptualizations of parenting. Further, through research-practice partnerships, cultivating a sense of purpose, apart from educational and career goals, emerged as significant for maintaining academic engagement and navigating an unstable and insecure job market. As president of SRCD (2021-2023), I emphasized and catalyzed transdisciplinary, multisector research to support children and families.