Language-impaired preschoolers: a follow-up into adolescence.
Stothard SE., Snowling MJ., Bishop DV., Chipchase BB., Kaplan CA.
This paper reports a longitudinal follow-up of 71 adolescents with a preschool history of speech-language impairment, originally studied by Bishop and Edmundson (1987). These children had been subdivided at 4 years into those with nonverbal IQ 2 SD below the mean (General Delay group), and those with normal nonverbal intelligence (SLI group). At age 5;6 the SLI group was subdivided into those whose language problems had resolved, and those with persistent SLI. The General Delay group was also followed up. At age 15-16 years, these children were compared with age-matched normal-language controls on a battery of tests of spoken language and literacy skills. Children whose language problems had resolved did not differ from controls on tests of vocabulary and language comprehension skills. However, they performed significantly less well on tests of phonological processing and literacy skill. Children who still had significant language difficulties at 5;6 had significant impairments in all aspects of spoken and written language functioning, as did children classified as having a general delay. These children fell further and further behind their peer group in vocabulary growth over time.