Facts About Stuttering
- National Stuttering Association
- Aug 7, 2024
- 3 min read
Updated: Oct 30
Understanding the Facts and Changing Perceptions
The more we understand stuttering, the better we can educate others about it.
The National Stuttering Association works with leading speech-language pathologists and researchers to provide reliable, up-to-date information about this communication difference.
Here are some of the most important, research-supported facts about stuttering.
When and How Stuttering Begins
Stuttering typically begins between the ages of two and five, when children’s language skills are rapidly developing.
About five percent of children experience a period of stuttering, though only around one percent of people worldwide continue to stutter long-term.
The onset can be gradual or sudden. Early intervention from a speech-language pathologist (SLP) can help families build confidence and respond supportively.
What Stuttering Looks and Feels Like
Stuttering involves involuntary speech interruptions called disfluencies.
These may include:
Sound or syllable repetitions (“n-n-no,” “wha-wha-whatever”)
Single-syllable word repetitions (“my my my”)
Sound prolongations (“ssssun”)
Blocks — moments when no sound comes out (“…you”)
People who stutter may also show physical tension or secondary movements such as eye blinks or facial twitches.
The sensation can feel like a loss of control, often leading to frustration or fear of speaking, especially if listeners react impatiently.
Genetic and Neurological Influences
Research shows that stuttering often runs in families and is influenced by genetics.
Brain-imaging studies reveal differences in the areas of the brain that coordinate language, timing, and motor control.
These neurological differences confirm that stuttering is a neurodevelopmental speech condition, not a learned behavior or psychological problem.
Children do not “pick up” stuttering by hearing someone else stutter.
For more insight, visit Causes of Stuttering.
Variability Is Normal
Stuttering naturally changes over time and across situations.
A person who once repeated sounds may later experience more blocking or prolongations. Some days speech may feel easier, while other days are more effortful.
This variability is normal and reflects how dynamic communication truly is. Periods of fluency do not mean stuttering has disappeared, and moments of struggle do not mean failure.
Who Is Affected by Stuttering
Stuttering occurs in every language and culture around the world.
It affects more males than females — roughly two boys for every girl in childhood and four men for every woman in adulthood.
About eighty percent of children who begin to stutter will recover naturally. Those who continue into their school years are more likely to stutter as adults.
Multilingual speakers often stutter in all their languages, though it may appear differently in each one. For instance, repetitions may occur more in one language and blocks in another. All of these differences are valid and normal.
Avoidance and Emotional Impact
Some people who stutter try to hide it by changing words, talking quickly, or avoiding situations where speaking feels difficult.
Although these behaviors may help in the moment, they can increase stress and reduce the joy of communication.
Therapy should address both the physical and emotional aspects of stuttering, supporting confidence, openness, and authentic self-expression.
The Experience Beyond Speech
For people who stutter, the visible speech differences are only part of the story.
The emotional, social, and psychological impact can be just as significant.
Supportive peers, understanding listeners, and community connection all help reduce stigma and build resilience.
The NSA provides safe spaces and education to ensure that people who stutter feel valued and understood. Explore our Local Chapters to connect with others who share your experience.
People Who Stutter Are Effective Communicators
People who stutter can be confident, engaging, and powerful speakers.
Fluency is not a measure of intelligence or ability.
With patience and understanding from listeners, communication can be clear, meaningful, and impactful — stuttering and all.
Learn more about therapy and support options on our Stuttering Treatment Options page.
Why Knowing the Facts Matters
Understanding the facts helps replace myths with truth.
It encourages patience, empathy, and inclusion in classrooms, workplaces, and communities everywhere.
When we share accurate information, we help build a world that listens and understands.
Continue learning on our Myths About Stuttering page.
References
Smith, A., & Weber, C. (2017). How stuttering develops: The multifactorial dynamic pathways theory. Journal of Speech, Language, and Hearing Research, 60(9), 2483–2505.
Yairi, E., & Ambrose, N. (2013). Epidemiology of stuttering: 21st century advances. Journal of Fluency Disorders, 38(2), 66–87.
Tichenor, S. E., & Yaruss, J. S. (2019). Stuttering as defined by adults who stutter. Journal of Speech, Language, and Hearing Research, 62(12), 4356–4369.
National Institute on Deafness and Other Communication Disorders (NIDCD). (2023). Stuttering.
Last Updated: October 2025
Author: National Stuttering Association Marketing & Education Team with contributions from Nicole Kulmaczewski, MS, CCC-SLP and Jacqueline Toscano, SLP.D. CCC-SLP