Why do people stutter?

The exact cause of stuttering is not known although there are several theories, for example this excerpt from: http://neurology.health-cares.net/stuttering-causes.php What causes stuttering? Although the exact cause of stuttering is not known, there are three leading theories that propose how stuttering develops. The learning theory proposes that stuttering is a learned behavior and that most normal children are occasionally disfluent (i.e. speaking rapidly, searching for the right words, etc.) when at the age at which speech and language develop. If a child is criticized or punished for this, he or she may develop anxiety about the disfluencies, causing increased stuttering and increased anxiety. The second theory suggests that stuttering is a psychological problem-that stuttering is an underlying problem that can be treated with psychotherapy. The third theory proposes that the cause ... more