While much research has focused on understanding the process by which young children learn to count, little work has explored the effects of direct instruction on this process. In the current study, we explored the impacts of training children in an explicit counting procedure on two distinct cardinality tasks. Two- to 5-year-old children first…

There is renewed interest in person-centered approaches to understanding the structure of temperament. However, questions concerning temperament types are not frequently framed in a developmental context, especially during infancy. In addition, the most common person-centered techniques, cluster analysis (CA) and latent profile analysis (LPA),…

Longitudinal data from a large sample of twins participating in the Netherlands Twin Register (n = 42,827, age range 3-16) were analyzed to investigate the genetic and environmental contributions to childhood aggression. Genetic auto-regressive (simplex) models were used to assess whether the same genes are involved or whether new genes come into…

An important aspect of perspective-taking ability is the appreciation that mental states such as beliefs, desires, and knowledge change over time. The current study focused specifically on 3-, 4-, and 5-year-olds' understanding that they will have knowledge in the future that they do not currently possess--for example, that when they are…

Based on Marcia's theory, many researchers consider exploration and commitment as the main processes in identity development. Although some identity theorists have hypothesized that emotional experience may also be an important part of the mechanisms of identity development, empirical research to investigate this claim has been lagging behind. In…

Working memory is a basic cognitive process that predicts higher-level skills. A central question in theories of working memory development is the generality of the mechanisms proposed to explain improvements in performance. Prior theories have been closely tied to particular tasks and/or age groups, limiting their generalizability. The cognitive…

The present study examined the effects of socioeconomic status (SES) and sibling differences in birth weight on sibling differences in the receipt of maternal sensitivity (i.e., differential parenting). It was hypothesized that sibling differences in birth weight would predict "absolute" differential parenting across the sibship (i.e.,…

In previous studies, older as compared with younger individuals were more strongly motivated to regulate their momentary affect toward pleasant and calm states. Whether these motivational differences are also reflected in regulatory behavior and whether this behavior is efficient in terms of affect change, however, is unclear. To address these…

Conflict adaptation is key in how children self-regulate and assert cognitive control in a given situation compared with a previous experience. In the current study, we analyzed event-related potentials (ERPs) to identify age-related differences in conflict adaptation. Participants of different ages (5-year-old children, 10-year-old children, and…

The current study examines the extent to which participation in preschool at age 4 is associated with blood pressure, body mass index, and awakening cortisol at age 15. We capitalize on data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development to examine differences in adolescent health…

Many researchers have used the standard Iowa Gambling Task (IGT) to assess decision-making in adolescence given increased risk-taking during this developmental period. Most studies are cross-sectional and do not observe behavioral trajectories over time, limiting interpretation. This longitudinal study investigated healthy adolescents' and young…

Fragmented sleep is common in infancy. Although night awakening is known to decrease with age, in some infants night awakening is more persistent and continues into older ages. However, the influence of fragmented sleep on development is poorly known. In the present study, the longitudinal relationship between fragmented sleep and psychomotor…

Saccade latency is widely used across infant psychology to investigate infants' understanding of events. Interpreting particular latency values requires knowledge of standard saccadic RTs, but there is no consensus as to typical values. This study provides standard estimates of infants' (n = 194, ages 9 to 15 months) saccadic RTs under a range of…

Paying attention is a critical first step toward learning. For children in primary school classrooms there can be many things to attend to other than the focus of a lesson, such as visual displays on classroom walls. The aim of this study was to use eye-tracking techniques to explore the impact of visual displays on attention and learning for…

Preschool children's use of decontextualized language, or talk about abstract topics beyond the here-and-now, is predictive of their kindergarten readiness and is associated with the frequency of parents' own use of decontextualized language. Does a brief, parent-focused intervention conveying the importance of decontextualized language cause…