Vocabulary knowledge was tested in a native (Cantonese-Chinese) and foreign (English) language in 150 twins and 150 singletons aged 6-11 years, matched on age, gender, grade level, nonverbal intelligence, parents' education, family income, and number of siblings and household members. The singletons clearly outperformed the twins on the native…

Using strict and lenient mathematics achievement cutoff scores to define a learning disability, respective groups of children who are math disabled (MLD, n = 15) and low achieving (LA, n = 44) were identified. These groups and a group of typically achieving (TA, n = 46) children were administered a battery of mathematical cognition, working…

This study examined the effect of exemplar typicality on reaction time and accuracy of categorization. High-functioning children (age 9-12), adolescents (age 13-16), and adults with autism (age 17-48) and matched controls were tested in a category verification procedure. All groups showed improved processing throughout the lifespan for typical and…

Recent research has found that the acquisition of theory of mind (ToM) is delayed in children with specific language impairment (SLI). The present study used a battery of ToM and visual perspective taking (VPT) tasks to investigate whether the delayed acquisition of ToM in children with SLI is associated with delayed VPT development. Harris'…

Research suggests that children with specific language impairment (SLI) have processing limitations; however, the mechanisms involved have not been well defined or investigated in a theory-guided manner. The theory of constructive operators was used as a framework to explore processes underlying limited processing capacity in children with SLI.…