Major advances have been made over the past two decades in delineating and understanding the communication and language difficulties of children with autism. The characterization of communication deficits in the diagnostic criteria for autism has changed dramatically. Until about 1980, peculiar speech patterns were emphasized, such as echolalia, pronoun reversal, and unusual intonation (Baltaxe and Simmons, 1975; American Psychiatric Association, 1980). Now, verbal and nonverbal communication are considered a core deficit in the diagnostic criteria for autistic spectrum disorders (American Psychiatric Association, 1987; 1994). This change highlights the recognition that children with autistic spectrum disorders not only have difficulty in the acquisition of speech and language, but also have difficulty understanding and using nonverbal behavior in communicative interactions.
The level of communicative competence attained by individuals with autism has been found to be an important predictor of outcome (Garfin and Lord, 1986; McEachin et al., 1993). The presence of fluent speech (using multiword combinations spontaneously, communicatively, and regularly) before the age of 5 continues to be a good prognostic indicator of IQ scores, language measures, adaptive skills, and academic achievement in adolescence (Venter et al., 1992). Moreover, the severity of the communicative impairment may be one of the greatest sources of stress for families (Bristol, 1984).
There is much heterogeneity in the speech, language and communication characteristics of children with autistic spectrum disorders. Language impairments in autistic spectrum disorders range from failure to