Williams syndrome (WS) is a rare genetic syndrome. As with all rare syndromes, obtaining adequately powered sample sizes is a challenge. Here we present legacy data from seven UK labs, enabling the characterisation of cross-sectional and longitudinal developmental trajectories of verbal and non-verbal development in the largest sample of…

Prenatal folate and vitamin B[subscript 12] status have been linked to child neuropsychological development, but less is known about maternal genetic influences on this association. We conducted an exploratory longitudinal study of 181 mother--child pairs to assess whether maternal MTHFR 677C>T genotype modifies the association between maternal…

Socialization is the process of learning to be a human being that is born with the potential to be human. In this process, the person learns the basic values and norms of the society in which he lives, as well as the skills necessary to sustain his life. This learning takes place through parents, siblings, relatives, neighbors, peers, teachers,…

Observed genetic associations with educational attainment may be due to direct or indirect genetic influences. Recent work highlights "genetic nurture," the potential effect of parents' genetics on their child's educational outcomes via rearing environments. To date, few mediating childhood environments have been tested. We used a large…

Purpose: Past research shows that parentally responsive behavior toward the child positively influences language development in both neurotypical children and children with intellectual and developmental disabilities, including those with fragile X syndrome (FXS); however, most studies have focused exclusively on the mother--child relationship.…

Background: Rubinstein-Taybi syndrome (RSTS) is a multiple congenital anomaly syndrome characterised by several typical somatic characteristics and by developmental disabilities with various degrees of severity. Focusing on children with RSTS, the aim of this study was to describe their psychomotor, cognitive, and socio-emotional developmental…

Given the importance of writing for academic achievement, this study aimed to understand how early oral language contributes to later writing skills. The first objective was to determine if preschool language skills were associated with high school writing, and if so, whether they contributed directly or indirectly through school age language. The…

Both genes and the environment are important for individual differences in expertise, but little is known about gene-environment interactions underlying domain-specific achievement. Here we explored this issue in a large Swedish twin cohort (N = 6,610), using moderator modeling with musical expertise as a model domain. Specifically, we tested…

Contemporary educational policies both at international and national levels acknowledge the educational rights of all children and their inclusion in mainstream educational practices. Like other children at risk, children with disabilities have opportunities to access mainstream education but their participation is not always realised in practice.…

According to Lev S. Vygotsky (1896-1934), the highest levels of abstract thinking and self-regulation in preschool development are established in "pretend play using object substitutions." An extensive research literature supports Vygotsky's empirical model of the internalization of self-guiding speech (social speech > private speech…

Background: The present study aimed at investigating mother-child dyadic co-regulation patterns in dyads with children with intellectual disability (ID). Method: 24 children paired for developmental age and vocabulary size (8 with chromosome 14 aberrations, 8 with Down syndrome, and 8 with typical development) and their mothers participated in the…

Individuals with sex chromosome trisomies (SCTs) have an increased risk of language delays and impairments. However, there are only a few data relative to their language development in early childhood. The present study aimed to investigate the preverbal skills shown by a group of 8-month-old children with SCTs to assess the presence of a possible…

Purpose: Variability in the timing of infant developmental milestones is poorly understood. We used a twin analysis to estimate genetic and environmental influences on motor development and activity levels in infancy. Method: Data were from the Gemini Study, a twin birth cohort of 2,402 families with twins born in the United Kingdom in 2007.…

Autism spectrum disorder (ASD) and autism-like traits are associated with deficits in face memory ability, although it is not yet clear whether this deficit reflects a specific aspect of the ASD/autism-like phenotype. We addressed this issue using a neurotypical sample of adolescent twins (N[subscript complete pairs] = 782) drawn from the Twins…

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…