The ‘Warnock Report’ (DfES, 1978) underlined the importance of early intervention for children with a range of special educational needs and the importance of partnership with families. This paper focuses on young children with intellectual disability to describe the longitudinal research on early development that has emerged since the report, and to describe the impact of that work on the scholarly literature that is available to inform practice.
First, we conducted a systematic literature search for primary reports of longitudinal studies focused on the early development of children with intellectual disability. Included studies were those that measured dependent (i.e., developmental outcomes) and independent variables (i.e., risk and resilience factors) at least on two measurement occasions (i.e., truly longitudinal) starting before the end of the 7th year of life for samples including children with intellectual disability (under labels such as global development delay or specific conditions such as Down syndrome). The topics of these studies as well as the publications that have cited these longitudinal studies were extracted with machine reading of titles and abstracts and subjected to multidimensional clustering (VOSviewer; Van Eck & Waltman, 2019). The resulting body of 101 research studies (about 2.5 studies per year) covered a scattering of topics without a dominant focus. The 3,491 scientific publications citing the longitudinal studies revealed three clusters of topics, dominated by (1) syndrome and disorder related terms; (2) autism-related terms; and (3) disability and parent related terms. Topics related to autism and, to a lesser extent, parents showed the strongest increase over time. Topics related to intervention and programs were most strongly linked to the topics disability and parents.
Against the background of the science thus mapped and the context for research in intellectual disability, we provide suggestions for a research agenda that addresses potential mismatches between development research and early intervention for children with intellectual disability and their families.
