Intellectual and Daily Living Skills of 30‐year‐olds with Down's Syndrome: Continuation of a Longitudinal Study

A cohort of infants with Down's syndrome (DS) born in 1964 were followed up again at the age of 30. They were tested on intelligence, language, reading and arithmetic, and their daily living skills were assessed. Comparison with the same tests given 9 years earlier showed almost no change. As before, higher scores were found for the women, those brought up at home, and, for language and reading, for those from social class nonmanual (NM) families but fewer of the differences were now significant. These results, demonstrating considerable stability over the period from age 21–30, are discussed with reference to other relevant research.