ABSTRACT
This chapter describes the breadth of individual differences (ID) across multiple domains of language acquisition. It considers how IDs are related to two complementary forces in child development: stability and change and the implications of IDs in language acquisition for education and clinical services. IDs are a common feature of human cognition as manifest in measures of attention, memory, and learning. A combination of wide IDs in language ability at every developmental stage coupled with a changing developmental pattern of language stability poses considerable challenges for the identification and treatment of children with low levels of language proficiency. A focus on IDs naturally gives the impression that stability and change are likely due to characteristics of the individual and their responses to environmental inputs. One may therefore consider whether IDs in other child characteristics may modify stability and change in language.
