[...] imperfect specialization of the two cerbral hemispheres: in the normal speaker the left hemisphere (or, if he is left-handed, the right hemispehere) dominates the more delicate actions, such as those of speech; in the stutterer this one-sided specialization is incomplete. Imperfect production of specific sounds ('stammering'), where it is not due to anatomical defects in the organs of speech, seems to result from similar maladjustments.
- Bloomfield (1935), Pag. 34