- Stammering tends to run in families. If there is someone else in a personís immediate or wider family who stammers, or who used to stammer, then that suggests an inherited or Ďfamilialí vulnerability.
- So, what is inherited? Brain imaging studies have shown that people who stammer tend to process speech signals in the brain slightly differently than people who do not stammer. They also seem to have slight structural differences in some areas of the brain. These differences in brain structure and function, which appear to develop early in childhood, are likely to be key in understanding why stammering develops for some people.
- Research has also shown that people who stammer, as a group, tend to be slightly slower at making the movements involved in speaking, for example getting voice started in the larynx or moving from one speech sound to the next. The implication of this is that speaking rapidly potentially puts a lot of pressure on a vulnerable speech motor system and this can destabilise fluency. Taking time pressure off, for example by speaking a little more slowly, is often helpful.
Adults - why do some people stammer?
A lot of different things can help to explain why someone starts to stammer in the first place, and a lot of things can influence day-to-day fluency.
- Language processing factors may also contribute. Some people who stammer relate to the idea of needing more time to gather their thoughts before speaking, especially when wanting to say something more complex. People may stammer more when they are under time pressure and donít have enough time to organize what they want to say.
People who stammer often say that they have more natural fluency when things are going fairly smoothly in life and when they are speaking in relaxed situations, for example when speaking with people who know them well. Conversely, people may stammer more in situations which are more challenging, such as talking to someone for the first time, speaking in a group, interview or meeting, or speaking on the telephone.
- Stammering is not caused by anxiety. Some, but not all, people who stammer do experience higher levels of anxiety in social situations, often because of their past experiences. Other emotions that people may experience include embarrassment, being ashamed about stammering, feeling down or depressed because of it, or feeling guilty about not speaking fluently.
- Many people find that this is a valuable area to focus on in therapy. There are different psychological therapies which are commonly included in therapy for stammering. Cognitive-Behaviour Therapy (CBT), Acceptance and Commitment Therapy (ACT), Solution Focused Brief Therapy (SFBT) and other approaches all offer ways to work with thoughts and feelings and build confidence and self-acceptance.
Occasionally, people can start to stammer in adult life when they have never stammered before as a child. This is called an acquired stammer and it may be the result of neurological or psychological factors.