The epigenesis of stuttering.

UNLABELLED This paper examines the data on which the Demands and Capacities Model (DCM) is based with the purpose of identifying areas where future research might determine consilience among genetic influences at the physiological, behavioral, and cultural levels. The determination of consilience across different levels would tend to validate the genetic influence on stuttering, but more importantly it would also sharpen the focus of researchers interested in the various possible expressions that genetic influences might have and the way in which they influence the development of the disorder. EDUCATIONAL OBJECTIVES The reader will (1) learn about the distinction, as outlined in the DCM, between environmental/contextual influences on stuttering development and intrinsic/genetic influences on stuttering development; (2) learn about the concept of consilience and its usefulness in conferring validity on parallel constructs at the physiological, behavioral, and cultural levels of stuttering theory; and (3) be able to identify potential areas for research that might help in refining our understanding of the genetic influences on stuttering development.