Retraining left-handers and the aetiology of stuttering: the rise and fall of an intriguing theory.

Many twentieth-century British and American educators, psychologists, and psychiatrists advocated forcing left-handed children to write with their right hands. These experts asserted that a child's decision to rely on his or her left hand was a reflection of a defiant personality that could best be corrected by forcible switching. The methods used to retrain left-handers were often tortuous, including restraining a resistant child's left hand. In contrast, those who saw left-handedness as inherited, but natural, not only disapproved of forced switching, but also often warned of its putative negative consequences, especially stuttering. These claims were given credence in the 1930s by influential University of Iowa researchers, including psychiatrist S. T. Orton, psychologist L. E. Travis, and their students. From the late 1920s until the 1950s, the Iowa researchers published articles and books connecting the etiology of stuttering to forcing natural left-handers to write and perform other tasks with their right hand. Based on their clinical studies these practitioners concluded that stutterers displayed weak laterality. The Iowa group also published detailed case studies of patients whose stuttering was putatively cured by the restoration of their left-handedness. By the late-1940s, the connection between stuttering and retraining evaporated, due in large part to the growing dominance of psychoanalytic psychiatry. Despite robust statistical and clinical evidence, the connection between forced hand switching and stuttering has largely been forgotten. Recent imaging studies of stutterers, however, have suggested that stuttering is tied to disturbed signal transmission between the hemispheres. Similar to the Iowa researchers of the 1930s, current investigators have found connections between stuttering and weak laterality.