Cognition and language development in autism.

A nonverbal assessment procedure was designed to characterize cognition using a Piagetian framework. Six autistic children, five echolalic and one nonverbal, ranging in age from 4:8 to 15:2, participated in this study. Cognitive and language performance was assessed using a developmental stage model. All six children evidenced competence beyond sensorimotor Stage VI, and demonstrated cognitive functioning between the periods of early preoperational and concrete operations. For five of the six children, the stage of cognitive development exceeded that of language development. The application of a developmental model for assessment purposes and theoretical implications of the results are discussed.