ABSTRACT
By far the most influential theory of developmental dyslexia, at least historically, has been that of Samuel Torrey Orton (e.g., 1937). His extensive observations in the 1920s and 1930s persuaded him that dyslexic children were especially prone to left-right confusions and reversals, such as mistaking b for d or was for saw, or writing in mirrored script. Many were also left-handed, or showed evidence of mixed laterality. Orton concluded that developmental dyslexia was due to a failure to establish a left-right sense, which was in turn caused by incomplete cerebral dominance. There are still many people who, even if they have not heard of Orton, regard dyslexia as virtually synonymous with "seeing things backward," or who regard left-or mixed-handedness as ominous signs of potential reading difficulty.
