Stuttering is a common language disorder that affects the way an individual speaks. People who stutter know what they want to say, but they have trouble fluently expressing themselves; they may repeat or prolong words or take long pauses between words in a sentence. If you or your child has a stutter, read on to learn about causes, symptoms, and treatments.
Onset and prevalence
For most people, stuttering, or childhood-onset fluency disorder, starts before the age of 5. There are some instances of individuals with onset after the age of 6, which can be attributed to individual differences.
During the childhood years, there are no differences in the prevalence of stuttering between genders, meaning that both boys and girls experience stuttering. However, the prevalence rates of stuttering later in adulthood are significantly different, with males 4 times more likely to stutter than females. This points to differential recovery rates in women.
The overall lifetime incidence rate of stuttering is estimated to be around 5%, meaning that there is a 5% chance for an individual to experience stuttering throughout their lifetime.
Types and causes
Broadly, stuttering is divided into two categories:
- Persistent type
- Recovered type
When children develop, they acquire the skill of language gradually, meaning that they slowly increase their vocabulary, perfect their pronunciation, and improve their overall fluency in expressing their thoughts verbally. Therefore, stuttering is considered part of the development process. There are vast individual differences in how quickly a child will develop verbal fluency, as well as whether any intervention for stuttering is needed.
Most children outgrow stuttering naturally, which is called recovered type. Sometimes stuttering persists into adolescence and adulthood, which is then referred to as persistent type stuttering.
The symptoms of stuttering, as well as their severity, can vary slightly on an individual basis. A child with stuttering will exhibit one or more of the following characteristics.
- Problems with initiating a phrase, sentence, or particular words.
- Pauses or breaks within words (breaking the word) or brief silence before certain letters or syllables.
- Extensive use of “filler words” to mask extensive pauses (e.g., “um”, “ehr”).
- Repetition of phrases, sentences, or words.
- Unnaturally prolonging particular syllables, words or letters (not to be confused with a particular dialect or accent characteristics).
- Limited ability to express oneself as intended.
- Sense of anxiety in verbal situations (e.g., public speaking, communicating with peers, verbal assignments, tasks).
Visible expressive characteristics:
- Tension, tightness, or movement of the face or upper body in connection to initiating word, sentence, or speech (e.g., clenching fists).
- Rapid eye blinks while talking or initiating verbal communication.
- Tremors of the lips or jaw that can be very slight (barely observable) or severe (very observable)
- Tics of the face.
- Involuntary head movements, such as jerks or twitches.
These symptoms might be triggered or become more pronounced in stressful situations or at times of increased self-consciousness. For example, when one needs to present in front of a group or has to introduce themselves to an unknown group.
When an individual is alone or relaxed, the symptoms might lessen, disappear, or become barely noticeable. It is also common for people with stuttering to be able to sing without any symptoms.
With the 21st century advance in research and genetic phenotyping, it is now established that stuttering has a significant genetic factor. Even though studies done on monozygotic and dizygotic twins do not always report the same percentage of inheritance, it tends to be on the high side, ranging from 55% to 85% with slight differences between genders and populations. Unfortunately, the concrete genes that cause stuttering are not known, and it is stressed that this area needs further focus from the research community.
It is assumed that there are environmental causes of stuttering, but it has not been clearly formulated what exact environmental factors play a role in developing stuttering. Some studies have looked at socio-economic factors that may influence the development of stuttering. However, it has been proposed that correlational relationships between income and stuttering are more indicative of treatment access than the development of stuttering itself.
The common misconception that stuttering is more prevalent in bilingual children has been shown to be incorrect, and the number of languages spoken in the family seems to have no effect on stuttering development.
The primary treatment for stuttering is speech therapy. This type of treatment involves training the way individual talks and working on particularly challenging words, syllables, or sentences. It can involve slowing down the tempo of speech and practicing slowly up until eventually getting up to a normal pace of talking. In addition, a speech pathologist may suggest electronic wearable devices that mimic your speech and help you to slow it down.
Sometimes cognitive behavioral therapy (CBT) is suggested as a form of treatment. CBT focuses on learning to cope with challenging or stressful situations and how an individual responds to them. Successful treatment allows for fluent speech patterns even at times of triggers, such as public speaking.
Overall, stuttering has high recovery rates that range from 40% to 80%, either through naturally “outgrowing” this speech pathology or successful treatment. Family involvement has been shown to be very beneficial in overcoming the stuttering.
Stuttering is quite common, and is part of developing language in children.
Stuttering can be naturally outgrown or persist into adulthood.
Stuttering is most likely to manifest before the age of 5.
Stuttering has a high inheritance rate.
Speech therapy is the main treatment for stuttering.
Recovery rates for stuttering are high.
Büchel, C., & Sommer, M. (2004). What causes stuttering?. PLoS biology, 2(2), e46.
Yairi, E., & Ambrose, N. (2013). Epidemiology of stuttering: 21st century advances. Journal of fluency disorders, 38(2), 66-87.