A reliable and practical subtype system of stuttering should enhance all related scientific work concerned with this disorder. Although a fair number of classification systems have been offered, to date, none has received wide recognition or has been routinely applied in research or clinical spheres. Whereas progress has been made in understanding…

This article reviews and critiques the research on possible genetic factors in stuttering. The failure to consider epidemiologic factors is thought to have biased previous research, but recent data provide evidence that spontaneous recovery and chronicity are influenced by genetic factors. Findings support previous conclusions about combined…