Linguistic imitation in children with Down syndrome.

Rate of linguistic imitation by 48 children with Down syndrome was compared to that of 57 children without mental retardation. Both groups were taken from different corpora within the Child Language Data Exchange System (CHILDES, MacWhinney, 1991). All speech data were collected from spontaneous speech samples of mothers interacting with their children. Three types of imitative utterances (exact, expanded, and reduced) were coded using an automatic data analysis program called CHIP (Sokolov & MacWhinney, 1990). Multiple regression was utilized to test for group differences while controlling for variability in MLU. The results indicated that children with Down syndrome imitated slightly less, but the exact nature of this difference was related to language level and the source of the imitation. As MLU increased, the rate of imitation decreased at a much steeper rate for children without mental retardation than for children with Down syndrome. In addition, children with Down syndrome showed a different pattern of results for imitations of their mothers than for self-repeated imitations. The results suggest that children with Down syndrome develop differently with respect to linguistic imitation.