Environmental change and psycholinguistic ability of mentally retarded adults.

Effects on linguistic ability of transferring retarded adults from a large institution to small "family" bungalows were examined. Effects of environmental change on linguistic ability were assessed using the Illinois Test of Psycholinguistic Abilities (ITPA) and by video-tape recordings of subjects engaging in speech. Results indicated that the bungalows had more resident-oriented as opposed to institution-oriented practices and more staff-resident interaction than did the large institution. The residents to be transferred were matched with control subjects who remained in the large institution. The ITPA was administered and resident interviews were video taped for both groups immediately before the transfer date and 9 months later. Psycholinguistic ability improved significantly more for transferred residents than for control subjects. Transferred residents increased the number of words used in affirmative and negative replies to simple questions during the videotaped interview, but there were no indications of any progression from one language stage to the next. The findings are comparable to previous studies concerning environmental change and increase in language ability of retarded children.