A foundational mechanism underlying human cooperation is reciprocity. In the context of repeated interactions with others, it is not always clear the degree to which in-kind responses reflect responsiveness to partners' prior behaviors ("reactive" responses), an interest unrelated to the partner ("nonreactive" responses), or…

As young as 3 years old, children rely on a mutual intentionality framework to confer group membership--that is, agreement between a joiner ("I want to be in your group") and group ("We want you to be in our group"). Here, we tested whether children apply this cognitive framework in the context of identity-based groups,…

It is widely accepted that investing in early childhood helps build the foundations of a healthy, productive, and equitable society. Guided by that knowledge, a range of broad-based programs and targeted services make a significant difference for millions of children, yet a closer look at outcome data shows that some benefit greatly, some benefit…

On a daily basis, children make decisions about how to negotiate their physical environment. Sometimes they engage in physical tasks that involve risk, requiring them to judge the safety of how to negotiate the environment safely. Individual differences in children's age, sex, physical size, and personality may impact those decisions. We used…

Students' experiences of physical education (PE) are considered important for lifelong attitudes towards physical activity. Sex-related differences and the individualised tempo in anthropometric growth because of biological maturation lead to secondary school students within chronological age-ordered classes possessing vast differences in…

Background: Adverse childhood experiences (ACEs) have long been associated with attention-deficit/hyperactive disorder (ADHD) diagnoses in children; but the data used is now over 6 years old (from 2017 to 2018). Understanding the current landscape of their prevalence and association is needed to capture evolving social, environmental, and economic…

Pretend play is one of the most beneficial and complex forms of play that promotes a myriad of children's development. Children's engagement in pretend play can be influenced by their genders, age, material or toys available, and adults' support. Pretend play has been long studied globally, however, there is still a dearth of available information…

Language development plays a pivotal role in a child's cognitive and overall growth, progressing through identifiable stages that ultimately lead to adult communication. It serves as a significant indicator of a child's intellectual and overall development. This study aims to explore the impact of daily technology use on children's language…

The development of executive function (EF) has been linked to various life outcomes, motivating intense research on the topic. While much of this research has focused on more thoroughly understanding age-related changes of the underlying neurocognitive mechanisms involved, recent theoretical and empirical works have stressed how the immediate…

Across all cultures, parents have intuitive ideas ("ethnotheories") of what undesirable child characteristics are as well as how to explain them. Yet there have been relatively few cross-cultural comparisons of parents' ethnotheories about the nature and causes of child misbehavior. 108 mothers of 5-year-old children from the United…

Extensive research demonstrates the far-reaching impacts of early childhood development (ECD) interventions, including both pre-primary education (PPE) and in-home nurturing. At the same time, a limited understanding of inequalities in ECD exposure across groups of children in many countries poses a fundamental challenge to effective policymaking.…

Across two studies, children ages 6-9 (N = 160, 82 boys, 78 girls; 75% White, 91% non-Hispanic) rated an inaccurate expert's knowledge and provided explanations for the expert's inaccurate statements. In Study 1, children's knowledge ratings decreased as he provided more inaccurate information. Ratings were predicted by age (i.e., older children…

Speech exhibits quasi-rhythmic regularities at multiple timescales, which seem to be crucial to comprehension. Both children's ability to extract rhythm from complex stimuli and to produce rhythmic patterns are known to undergo changes from infancy to adulthood. However, it remains unclear what rhythm skills specifically related to speech look…

Girls, more than boys, experience a decrease in the severity of autism symptoms during childhood. It is unclear, however, which specific autistic behaviors change more for girls than for boys. Trajectories of autism symptoms were evaluated using the Autism Diagnostic Observation Schedule-calibrated severity scores (ADOS-CSS). Change in the…

Background: Although research clearly demonstrates the importance of motivation in mathematics learning, relatively little is known about the developmental dynamics between different facets of mathematics motivation and performance, especially in the early years of schooling. Aims: In a longitudinal setting, we examined (1) how children's ability…