Background: Autistic people without intellectual disabilities have increased perceptual capacity: they can process more information at any given time compared to non-autistic people. We examined whether increased perceptual capacity is evident across the autistic spectrum (i.e. for autistic people with intellectual disabilities) and whether it is…

Background: Studies in Down syndrome (DS) and Williams syndrome (WS) have suggested that mathematical abilities are impaired. However, it is unclear which domain-general or domain-specific abilities impact on mathematical development in these developmental disorders. Method: The current study examined the foundations of mathematical development…

Background: Angelman syndrome (AS) leads to clinical manifestations that include intellectual impairments, developmental delay and poor motor function. Initiatives to develop therapeutics imply an urgent need to identify methods that accurately measure the motor abilities. Methods: Six children with AS (6 to 9 years old) walked on an instrumented…

Background: This study explores everyday social competence in the lives of persons with three genetic intellectual disability syndromes. Methods: Using parent reports on the Social and Activity Competence domains of Achenbach's Child Behavior Checklist (CBCL), socially competent behaviours were examined in 58 persons with Williams syndrome, 54…