The standard view on Theory of Mind (ToM) is that the mastery of the false belief (FB) task around age 4 marks the ontogenetic emergence of full-fledged meta-representational ToM. Recently, a puzzling finding has emerged: Once children master the FB task, they begin to fail true belief (TB) control tasks. This finding threatens the validity of FB…

Metacognitive reasoning is central to decision-making. For every decision, we can also judge our trust in that decision, or our level of "confidence." The mechanisms and representations underlying reasoning about confidence remain debated. We test whether children rely on "processing fluency" to infer their own confidence: do…

This study aims to preliminarily validate the Italian version of the Coparenting Relationship Scale for Children (CRS-C) with 141 mothers, 141 fathers, and 141 children (48.6% males) aged 8-14 years. We tested the factorial structure of the CRS-C, which included five factors (support, endorsement, undermining, agreement, and exposure to conflict),…

Background: Identifying language disorders earlier can help children receive the support needed to improve developmental outcomes and quality of life. Despite the prevalence and impacts of persistent language disorder, there are surprisingly no robust predictor tools available. This makes it difficult for researchers to recruit young children into…

This study was conducted to determine how total fundamental movement skill (FMS) score and, separately, locomotor skill (LMS), and object control skill scores in children 3-8 years old predicted their specific-intensity physical activity 3 years later. Overall, 441 Finnish children (51.7% female, baseline mean age of 5.6 years) participated in the…

Understanding classroom-level correlates of preschool children's aggressive behavior is critical to identifying multiple avenues for intervention within schools. The present school-based study evaluated the reliability and validity of a classroom-level measure of physical and relational aggression and examined a social-ecological model to test…

Autistic individuals are twice as likely to meet criteria for anxiety than neurotypical children; yet we lack understanding of early presentations of anxiety in young autistic children, especially those with cognitive impairment. This study is the first to utilize an autism-specific anxiety diagnostic interview with 28 preschool cognitively…

This study examined the cognitive predictors and constraints of children's strategic offers in the Ultimatum Game. The Ultimatum Game is a one-shot negotiation on the division of a given sum of rewards between two people, where the receiver has the right to punish the proposer by rejecting unfair offers, which results in nil reward for either…

Children's ability to save emerges during the preschool years, but little is known about the different forms saving takes (and whether these relate) and the mechanisms driving its development. Because research with adults suggests that different aspects of future orientation increase adults' propensity to save, we explored whether, in a sample of…

Using the Early Childhood Longitudinal Study Kindergarten Cohort (2010-2011), this study is the first to investigate predictors of kindergarten science achievement and growth across elementary school--English language proficiency (ELP), executive functioning, math and reading achievement, parent-engaged science and math activities, and classroom…

Creativity researchers are increasingly interested in understanding when, how, and for whom creativity can be beneficial. Previous reviews have demonstrated that creativity research largely ignores the study of its impact on factors that promote health, and well-being among populations of adults. It is unclear, in fact, whether this gap in…

Children's fuzziness leads to increased variance in the data, data loss, and high dropout rates in developmental studies. This study investigated the importance of 20 factors on the person (child, caregiver, experimenter) and situation (task, method, time, and date) level for the data quality as indicated via the number of valid trials in 11…

When children first learn to count, what do they understand about the structure of the count system? The present study investigated English-speaking children's ability to generalize the rules that structure their count list to novel contexts. A total of N = 86 children (3;0-6;11) completed a battery of tasks aimed at measuring their understanding…

We investigated performance levels on conducting continuous two-footed jumping of preschool children (4 years old) to high school students (16 years old) to clarify the developmental progression and sex differences in motor coordination and agility. In total, 450 children (boys: 227; girls: 223) participated in this study. We set 10 obstacles to…

This study examined children's emotion attributions and moral judgements to hypothetical procedural justice outcomes when the candidates were equal in merit but different in need. Children (7 to 11 years old, N = 88) were presented with four vignettes depicting resource-rich and resource-poor candidates losing educational materials and…