Twins regularly score nearly a standard deviation below the population mean on standardized measures of cognitive development in infancy but recover to the population mean by early childhood, making rapid gains through the toddler years. To date, only polynomial growth models have been fit to model cognitive recovery across childhood, limiting the…

Understanding gender differences in human cognitive development may contribute to understanding the gender differences in outcomes in cognitive ageing. However, evaluation of this topic has been hindered by a lack of representative, longitudinal data from different aged cohorts measured on the same cognitive tests. Gender differences in cognitive…

HIV-exposed uninfected (HEU) children during the preschool and early school ages may be at-risk for neurodevelopmental challenges due to in utero and perinatal exposure to HIV and/or antiretroviral (ARV) medications. HEU children and HIV-unexposed uninfected (HUU) children from the community were recruited and tested at 3 to 4 and 5 to 6 years of…

Recent studies indicate that premature children are at risk for difficulties with cognitive development and have increased incidence of ADHD as well as other behavioral disorders. Although the exact mechanism accounting for these children's neuropsychological abnormalities is unknown, there is evidence to suggest that the cognitive and behavioral…

Executive functions (EF) are domain-general cognitive skills that predict foundational academic skills such as literacy and numeracy. However, less is known about the relation between EFs and science achievement. The nature of this relation might be explained by the theory of mutualism, which states that development is the result of complex and…

Differentiation of intelligence refers to changes in the structure of intelligence that depend on individuals' level of general cognitive ability (ability differentiation hypothesis) or age (developmental differentiation hypothesis). The present article aimed to investigate ability differentiation, developmental differentiation, and their…

Neurological soft signs (NSSs), minor neurological abnormalities, have been implicated as risk factors for poor cognitive performance in small-scale studies. Here we investigate the associations between NSSs and multiple domains of cognitive performance in a large, population-based cohort and evaluate sex differences in these associations. We…

Differentiation hypotheses concern changes in the structural organization of cognitive abilities that depend on the level of general intelligence (ability differentiation) or age (developmental differentiation). Part 1 of this article presents a review of the literature on ability and developmental differentiation effects in children, revealing…

Throughout childhood and adolescence, humans experience marked changes in cortical structure and cognitive ability. Cortical thickness and surface area, in particular, have been associated with cognitive ability. Here we ask the question: What are the time-related associations between cognitive changes and cortical structure maturation.…

Although early life experiences of language and parenting are critical for children's development, large home observation studies of both domains are scarce in the psychological literature, presumably because of their considerable costs to the participants and researchers. Here, we used digital audio-recorders to unobtrusively observe 107…

We examined the development of 3 executive function (EF) components--inhibition, updating, and task shifting--over time in monolingual and bilingual school-age children. We tested 41 monolingual and 41 simultaneous bilingual typically developing children (ages 8-12) on nonverbal tasks measuring inhibition (the Flanker task), updating (the Corsi…

Several theories of executive function (EF) propose that EF development corresponds to children's ability to form representations and reflect on represented stimuli in the environment. However, research on early EF is primarily conducted with preschoolers, despite the fact that important developments in representation (e.g., language, gesture,…

Conceptual notions and empirical evidence suggest that the intraindividual correlation (iCorr) of positive affect (PA) and negative affect (NA) is a meaningful characteristic of affective functioning. PA and NA are typically negatively correlated within-person. Previous research has found that the iCorr of PA and NA is relatively stable over time…

A wealth of literature has examined the association between breastfeeding and the development of cognitive abilities in childhood. In particular, at least some evidence exists suggesting that breastfed children perform better on measures of intelligence later in life. Although a correlation appears to be present, fewer observational studies have…

Research has indicated age-related improvements in relational binding, an important process of episodic memory, across development. However, little research has focused on individual differences in relational binding and factors contributing to this variation. Although differences may arise from various sources, early caregiving has been shown to…