Responses to requests for clarification by older and young adults with mental retardation.

This study compared the ability of young (mean chronological age = 29 yrs., SD = 3.67 yrs.) and older adults (chronological age = 63 yrs., SD = 5.54 yrs.) with mild to moderate mental retardation to respond to stacked requests for clarification in conversation. Data were collected in dyadic conversations between subject and investigator. During the course of the conversation, the investigator introduced stacked sequences of three requests for clarification of the same message ("Huh?", "What?", "What?"). Neither group of subjects was as responsive to the requests for clarification as would have been predicted based on their general cognitive and linguistic levels of functioning. Few significant differences were observed between the young and older groups.