Children often answer questions when they do not have the requisite knowledge or when they do not understand them. We examined whether "ground rules" instruction--to say "I don't know," to tell the truth, and to correct the interviewer when necessary--assisted children in applying those rules during an interview about a past…

The present study explored the relations among lie-telling ability, false belief understanding, and verbal mental age. We found that children with autism spectrum disorder (ASD), like typically developing children, can and do tell antisocial lies (to conceal a transgression) and white lies (in politeness settings). However, children with ASD were…

This study investigates whether distinct neurodevelopmental disorders show distinct patterns of impairments in particular grammatical abilities and the relation of those grammatical patterns to general language delays and intellectual disabilities. We studied two disorders (autism and Williams syndrome [WS]) and two distinct properties (Principle…

Adults with autism spectrum disorders (ASD) have shown deficits in switching between rules governing their behaviour, as have high-functioning children with ASD. However, there are few studies of flexibility in lower-functioning children with ASD. The current study investigated this phenomenon with a group of low-functioning children with ASD…

This study compared mothers and fathers' regulation with respect to 29 children with intellectual disability (ID) and 30 typically developing (TD) children, matched on their mental age (MA), as they solved eight tasks using physical materials and computers. Seven parents' regulatory strategies were coded as they supported their child's…

The emergence of the Down syndrome (DS) behavioural phenotype during early development may be of great importance for early intervention. The main goal of this study was to investigate the good-imitator-poor-talker developmental profile in DS at preschool age. Twenty children with Down syndrome (DS; mean nonverbal mental age NMA 1 y10 m) and 15…

We used neuropsychological tasks to investigate integrity of brain circuits linking orbitofrontal cortex and amygdala (orbitofrontal-amygdala), and dorsolateral prefrontal cortex and hippocampus (dorsolateral prefrontal-hippocampus), in 138 individuals aged 7-18 years, with and without autism. We predicted that performance on…

A comparative observational study was undertaken of the spontaneous social interactions of children with high-functioning autism and Asperger's disorder. The sample comprised 20 children with high-functioning autism, 19 children with Asperger's disorder and 17 typically developing children matched on chronological age and overall mental age. A…

The social skills and problem behaviours of children with high-functioning autism and Asperger's Disorder were compared using parent and teacher reports on the Social Skills Rating System. The participants were 20 children with high-functioning autism, 19 children with Asperger's Disorder, and 17 typically developing children, matched on…

This pilot study was designed to examine mental rotation ability in individuals with Down syndrome. 7 individuals with Down syndrome (mean mental age = 8.18 +/- 2.73 years; mean chronological age = 29.8 +/- 5.4 years) and a group of 9 typically developing children, matched for mental age, (mean mental age = 8.40 +/- 1.73 years; mean chronological…