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

The team asked adults with mild or moderate intellectual disability to respond to stacked clarification requests. These are follow-up questions like "What?" or "Can you say that again?" asked two or three times in a row.

They split the group into younger adults and older adults. Then they watched who answered after each repeated request.

Most adults stayed quiet or gave the same short answer even after the third request. Age did not matter; both younger and older adults acted the same way.

The result did not match what their mental age scores predicted.

English et al. (1995) and Iacono et al. (2010) both saw receptive language drop as adults with Down syndrome get older. Brinton et al. (1996) saw no age split, but they tested a broad ID group, not just Down syndrome. The gap looks like a contradiction until you notice the diagnosis mix.

López-Riobóo et al. (2019) later tested young adults with Down syndrome and found bigger auditory than visual language gaps. Their data extend the 1996 point: even younger adults can miss spoken cues, so the issue is not simply aging.

Dudley et al. (2019) showed children with ID need a mental age near 7-9 years before tackling complex syntax. Together these papers warn us that both kids and adults with ID may not catch subtle spoken hints, no matter their birthday.

If a client ignores your second or third prompt, do not assume defiance or hearing loss. The 1996 data say repeated clarification requests often fail with adults who have ID. Switch modes: show a picture, write the key word, or model the answer once. Keep instructions short and add visual cues right away instead of stacking verbal repeats.