Philosophical and Theoretical Foundations of Developmental Language Disorder

This manuscript provides a comprehensive framework for the scientific study and clinical management of developmental communication disorders and in particular developmental language disorder. This framework is grounded in both the philosophy of cognitive science and psychology and in the philosophy of medicine. It acknowledges that notions of function and dysfunction are central to understanding developmental communication disorders. I will argue that functionalism and in particular mechanistic functionalism provides a strong basis for understanding individual differences in language performance in the form of interpretation and generation of messages. I further argue that there are no forms of variation in the functioning of this message mechanism that are inherently defective or disordered as would be expected within naturalistic account of health and ill-health within the philosophy of medicine. Instead, I argue that notions of health and ill-health have been shown to be grounded in cultural values. As such, in order to understand developmental language disorder, we must understand how language provides important functional utilities to individuals within their societies. In this regard, understanding developmental communication disorders requires and appreciation and articulation of both natural and social sciences.