Communicative competence and metalinguistic ability: performance by children and adults with autism spectrum disorder.

The Test of Language Competence-Expanded Edition (TLC-E) was administered to children and adults with a diagnosis of autism spectrum disorder (ASD). Relative to controls, those with ASD were less competent on a range of TLC-E tasks. No differences were found for either child or adult ASD groups on any of the TLC-E measures when re-classified as Asperger syndrome (AS) and high functioning autism (HFA) using DSM-IV language criterion. Hierarchical cluster analyses of individuals with ASD identified subgroups within the spectrum. The use of developmental language history as an identifying marker in autism is questioned. The findings suggest that comprehensive language assessments on individuals with ASD can provide clinically relevant information regarding the heterogeneity of language skills within the autistic spectrum.