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…

During adolescence, increases in pubertal hormones lead to reproductive maturity as well as changes in cognitive development. Yet, little is known about how to best characterize interindividual differences in hormone concentrations. The goal of the current study was to examine the antecedents and consequences of membership in empirically derived…

Cognitive tasks are seldom evaluated on their ability to provide valid and reliable measurements of the construct they intend to measure. This scarcity of psychometric evaluations makes it challenging to evaluate replications of experimental effects and to relate performance in cognitive tasks to other constructs of interest. In developmental…

The recent expansion of research on children's understanding of others' minds (or 'theory of mind', ToM) into middle childhood provides fresh opportunities to consider its origins and consequences. In this paper, we propose that, in addition to supporting children's social interactions, individual differences in ToM benefit academic achievement,…

Executive attention, the attention necessary to reconcile conflict among simultaneous attentional demands, is vital to children's daily lives. This attention develops rapidly as the anterior cingulate cortex and prefrontal areas mature during early and middle childhood. However, the developmental course of executive attention is not uniform among…

When children transition to school between the ages of 4 and 6 years, they must learn to control their attention and behaviour to be successful. Concurrently, executive function (EF) is an important skill undergoing significant development in childhood. To understand changes occurring during this period, we examined the role of parenting in the…

By 3?years of age, children generally have a firm understanding of others' reliability, but there is considerable variation among individual children. Little attention has been paid to factors that influence such individual differences. This study addressed this by assessing the relation between reliability understanding and temperament in…

Recent research has demonstrated that social responsiveness (comprised of social awareness, social information processing, reciprocal social communication, social motivation, and repetitive/restricted interests) is continuously distributed within the general population. In the present study, we consider temperament as a co-occurring source of…

Children's performance on cognitive tasks is often described in categorical terms in that a child is described as either passing or failing a test, or knowing or not knowing some concept. We used binomial mixture models to determine whether individual children could be classified as passing or failing two search tasks, the DeLoache model room…

Epistemic curiosity (EC) is the desire to obtain new knowledge capable of either producing positive experiences of intellectual interest (I-type) or of reducing undesirable conditions of informational deprivation (D-type). Although researchers acknowledge that there are individual differences in young children's epistemic curiosity, there are…

The present study compared indigenous South African versus African-American schoolchildren's beliefs about aggression. Eighty 7-9 year olds (40 from each country) participated in interviews in which they were asked to make inferences about the stability, malleability, and causal origins of aggressive behaviour. Although a minority of participants…

This review of 20 years of developmental research on Executive Functions (EF) offers a broad-brushstroke picture that touches on multiple issues including: (i) findings from typical and atypical groups, from infancy to adolescence; (ii) advances in assessment tools and in statistical analysis; (iii) the interplay between EF and other cognitive…

Through her theoretical and empirical work, Mary Rothbart has had a profound impact on the scientific understanding of infant and child temperament. This special issue honors her contributions through the presentations of original, contemporary studies relevant to three primary themes in Rothbart's conceptual approach: the expansive scope and…

Imitation is an important means by which infants learn new behaviours. When infants do not have the opportunity to immediately reproduce observed actions, they may form a memory representation of the event which can guide their behaviour when a similar situation is encountered again. Imitation procedures can, therefore, provide insight into infant…

The purpose of the current study was to investigate the development of sleep-wake and melatonin diurnal rhythms over the first 3 months of life, and the potential effect of bed-sharing on their development. It was hypothesized that increased maternal contact through bed-sharing would affect the development of rhythms in human infants. Ten…