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…

In this article, it is argued that it makes sense to define and distinguish three levels of human intelligence: intelligence as genotypical potential, intelligence as actualised in environmental interaction, and intelligence as measured by tests (IQ). This raises the questions of what is meant by the term "intelligence as potential", and…

Conoley, Powers, and Gutkin (2020) called for an increased emphasis on models of psychological service delivery that are primarily indirect, adult-focused, and geared toward systems-level change in the schools. They asserted that research in school psychology should not focus on the problems of individual children and youth but address the…

In the multidisciplinary field of developmental cognitive neuroscience, statistical associations between levels of description play an increasingly important role. One example of such associations is the observation of correlations between relatively common gene variants and individual differences in behavior. It is perhaps surprising that such…

Accurate understanding of environmental moderation of genetic influences is vital to advancing the science of cognitive development as well as for designing interventions. One widely-reported idea is increasing genetic influence on cognition for children raised in higher socioeconomic status families, including recent proposals that the pattern is…

Executive functions (EF) are an important predictor of later adaptive development. A number of environmental influences, such as parenting, have been suggested as important promoters of EF development. However, behavioural genetic research has demonstrated that many environmental influences could be affected by genetic influences. Therefore, it is…

The ability to acquire language is a critical part of human development. Yet there is no consensus on how the skill emerges in early development. Does it constitute an innately-specified, language-processing module or is it acquired progressively? One of Annette Karmiloff-Smith's (1938-2016) key contributions to developmental science addresses…

Each year, the Interagency Autism Coordinating Committee (IACC) releases a list of scientific advances that represent significant progress in the field. The "2020 Summary of Advances in Autism Research" provides short, plain language summaries of the top research breakthroughs selected by the IACC from a pool of research articles…

Although growth in head circumference (HC) during infancy is known to predict later childhood outcomes, the mechanisms underlying this association with later sociocognitive abilities remain undetermined. Thus, using a sample of 241 pairs of normally developing Japanese twins, this study investigated the underpinnings of the association between HC…

This research brief explores how emotions and relationships drive learning and are a fundamental part of how our brains develop. The authors explain how emotionally safe and cognitively stimulating environments contribute to brain development; how brain development that supports learning depends on social experiences; and how sensitive periods in…

Objective: Current research suggests that the causes of autism spectrum disorders (ASD) are multifactorial and include both genetic and environmental factors. Several lines of evidence suggest that epigenetics also plays an important role in ASD etiology and that it might, in fact, integrate genetic and environmental influences to dysregulate…

Individuals with Down syndrome are predisposed to show a specific behavioural phenotype, or a pattern of strengths and challenges in functioning across different domains of development. It is argued that a developmental approach to researching the Down syndrome behavioural phenotype, including an examination of the dynamic process of the unfolding…

Whereas some four year olds could draw a person with five fingers on each hand and a full set of facial features, others could barely hold a pencil. Some sat quietly in a small group, intently listening to and understanding a story, while others wiggled, fidgeted, and couldn't focus their attention. In those days, before the explosion of…

Objective: Child and adolescent psychiatry is rife with examples of the sustained effects of early experience on brain function. The study of behavioral genetics provides evidence for a relation between genomic variation and personality and with the risk for psychopathology. A pressing challenge is that of "conceptually" integrating findings from…

Chaos in the home is a key environment in cognitive and behavioural development. However, we show that children's experience of home chaos is partly genetically mediated. We assessed children's perceptions of household chaos at ages 9 and 12 in 2337 pairs of twins. Using child-specific reports allowed us to use structural equation modelling to…