ABSTRACT
This chapter reviews two theories that their authors identify as multifactorial. The demands and capacities (DC) model proposes that stuttering occurs when demands for fluency are greater than the child's capacity to produce it. Neither the child's capacity for fluency nor the demands placed on it are, in terms of the DC model, necessarily abnormal, deviant or disordered for stuttering to occur. The DC model proposes four developmental factors or capacities related to fluency: speech motor control, language development, social and emotional functioning, and cognitive development. The dynamic multifactorial (DM) model of stuttering is identified by its authors as multifactorial and interactional, with non-linear, dynamic relationships between and among the factors. Stuttering is seen as emerging from dynamically interacting factors rather than being the result of a single factor. The explanation of stuttering provided by the model, environmental factors dynamically interact with factors intrinsic to the individual; these intrinsic factors are genetic, organismic, emotional, cognitive and linguistic.
