stuttering or stammering, speech disorder marked by hesitation and inability to enunciate consonants without spasmodic repetition. Known technically as dysphemia, it has sometimes been attributed to an underlying personality disorder. About half of all those who have speech and voice defects suffer from stuttering or stammering (the terms are used interchangeably). In 65% of people who stutter, there is a family history of the disorder, thus suggesting a genetic link. Studies with twins have also indicated that inheritance has an important role in stuttering; comparing pairs in which at least one twin stuttered, it has been found that identical twins were much more likely to be stutterers than fraternal twins (see multiple birth). Brain scans of stutterers have found higher than normal activity in brain areas that coordinate conscious movement, suggesting that in people who stutter speech occurs less automatically than it does in most people.
In many instances the speech disturbance appears to be precipitated by such situations as a change of surroundings, the advent of a younger child in the family, or by a family environment in which parents are overly concerned with childhood speech interruptions, which occur normally. Negative reactions to the stuttering frequently create feelings of inadequacy and anxiety, which, in turn, intensify the condition. Parents with young children who stutter have been urged by specialists to help their children develop positive attitudes about themselves and their speech. Older stutterers are taught to understand what processes interfere with fluent speech and to speak without the disruptions caused by tension. Psychiatric treatment and group psychotherapy have been helpful for many.
See M. Jezer, Stuttering: A Life Bound Up in Words (1997).