ABSTRACT
Approaches to understanding language disorders typically emphasize inborn biological factors, acquired disabilities, and shaping through environmental pressures. Emergentist theory can provide a fuller and more integrated understanding of the causes, results, and development of language disorders. It does this by grounding explanations on analysis of neurolinguistic levels and the ways in which different levels are subject to mechanisms and constraints unique to each level. Emergentist analysis of this type is commonly applied for understanding all types of biological systems in terms of evolution, organ function, behavior, and species competition. This chapter reviews constraints that operate on linguistic levels and processes and discusses how they operate in online processing and across the lifespan to shape language in disorders such as aphasia and SLI.
