Developmental Trajectories of Reading Ability in Adolescents with Intellectual Disabilities

Abstract

ABSTRACT Individuals with ID often struggle with decoding and reading comprehension, and some studies indicate that these students do not progress beyond the early stages of decoding development. The aim of this study was to investigate the developmental trajectories of reading abilities in relation to mental age in a sample of 136 adolescents with mild, non-specific ID. Decoding and reading comprehension, together with their predictors of phonological awareness, RAN, phonological working memory, and vocabulary, were fitted against mental age. The results showed that, after 105 months, there was an unexpected plateau in the development of decoding, phonological awareness, rapid automatised naming (RAN), and phonological working memory in this sample, while reading comprehension and vocabulary continued to show growth in relation to mental age. The implications of these different trajectories are discussed in relation to developmental models of disability, and possible reasons for the plateau in decoding are suggested.