Stuttering and stammering

Stuttering and stammering

What do Marilyn Monroe, Winston Churchill and Irish politician Proinsias de Rossa all have in common? At some time in their lives, they were people who stutter. Clearly their speech disorders did not hinder them in pursuing very successful lives. For many other people who stutter, however, the combination of embarrassment, loss of control, and being made to feel stupid by non-stutterers can be devastating to self-confidence.

What is stuttering?

Stuttering, also known as stammering, is primarily characterised by repetitions, pauses, and prolongations in speech. Stuttering usually occurs on the initial sound or syllable of a word, in the first word of a sentence, on accented syllables, and on 'content' words. 'Content' words carry the meaning of a sentence, which is why when listeners guess what a stutterer is trying to say, they often get it wrong.

Stuttering usually starts around the time that language skills are developing, and onset is generally gradual in nature. Late-onset developmental stuttering is rare. Some stutterers will be more fluent in some situations than others and the same person can be more fluent at some times than others. This variability can cause tremendous frustration on the part of the stutterer.

Studies have shown that stuttering increases when saying one's name, speaking on the telephone, speaking to an authority figure, or speaking to an audience. Equally, stuttering decreases when saying a phrase repeatedly, speaking in chorus with another person, when speaking alone or to animals, when singing, using a lower pitch, using a different accent, using electronic anti-stuttering devices, and even when crawling on all fours.

How common is it?

Stuttering affects four times as many males as females. Some 25% of all children go through a stage of development during which they stutter. Around 4% may stutter for six months or more. As children get older, the prevalence drops to about 1% in primary and secondary school, and to about 1% for adults.

At two and three years of age, equal numbers of boys and girls stutter. The sex ratio becomes three males for every female by the age of five and four to one by the age of 10, the same ratio as adults. Of adult stutterers, 80% are men.

Does stuttering have a physical or psychological cause?

There is nothing wrong with stutterers' tongues, vocal folds or breathing. Stutterers are not more nervous, do not necessarily have worse self-esteem, and are as likely to be intelligent and well-adjusted as non-stutterers.

Stuttering is a developmental disorder. Some experts believe that stuttering develops from the normal mistakes all children make when learning to talk. While most children can pick themselves up after a stumble, some children get into a vicious cycle of trying harder to talk, tensing their speech production muscles too much, and getting more stuck.

Other experts have found that severe stuttering can develop almost overnight in young children. They believe that stuttering may not develop gradually from normal disfluencies or language difficulties. Genes have been found associated with stuttering, so some experts believe that a genetic defect causes something in the child's brain to trigger stuttering.

Although the origin of stuttering is not clear, everyone agrees that childhood stuttering can develop into a severe physical and psychological disability. Adults who stutter can have physical symptoms, including:

The psychological symptoms of adult stuttering can include:

Some stutterers are so good at avoidance that their co-workers and even their spouse or family don't know that the individual stutters. Even though their speech sounds fine, these 'covert' stutterers can be crippled by severe psychological fear and anxiety.

Some related complaints and variants on stuttering


Cluttering is what happens when speech becomes literally cluttered with faulty phrasing and unrelated words to the extent that it is unintelligible. Unlike stuttering, which involves hesitation and repetition over key words, cluttering usually includes effortless repetition of syllables and phrases. The affected person is often not aware of any communication difficulties.

Cluttering is a disturbance in the fluency of speech. People who clutter often speak at a more rapid rate than normal, which causes them to stumble and double back in their attempt to impart meaning. It is characterised by a poor attention span, perceptual weakness and poorly organised thinking.

Neurogenic stuttering

Strokes and head injuries can cause stuttering-like symptoms in adults. Neurogenic stuttering has repetitions, prolongations, and blocks. Neurogenic stutterers lack the facial grimaces, eye blinking, and fears and anxieties of developmental stuttering.

Psychogenic stuttering

Adult psychogenic stuttering begins suddenly after an event causing extreme psychological stress. It is characterised by repetition of initial or stressed syllables, lack of conditions inducing fluency, an indifferent attitude toward the disorder, and maintenance of normal eye contact. Psychogenic stuttering is rare.

Spastic dysphonia

Spastic dysphonia is a repeated blockage of the larynx. The onset is in middle age, and the disorder affects an equal number of men and women.

Tourette's syndrome

Tourette's syndrome is akin to stuttering with your hands and feet. Touretters compulsively touch objects, and some have verbal symptoms such as barking or saying obscenities. Like stuttering, these behaviours are situational, but trying to not do the behaviours makes the behaviour stronger.

Where can I get more information and help with stuttering?

Speech therapy can aid people who suffer significantly. Your GP can refer you to a therapist. For information and support for people who stutter, there is the Irish Stammering Association, a registered Charity founded in 1994. The Association seeks better help for both children and adults who stammer. They can advise doctors, health officials and the general public on the facts of stuttering.

Back to top of page