How Stuttering Works

Actress Emily Blunt speaks at the American Institute for Stuttering's Freeing Voices Changing Lives Gala. Cindy Ord/Getty Images for American Institute for Stuttering

Paul Stamets had a stutter — a bad one. His dad was an engineer and had a full-scale laboratory in the basement of their home. Stamets spent a lot of time in that basement, which makes sense, because stuttering can increase feelings of social isolation. He spent hours mixing explosive chemicals and nursing his plans to become a pioneering researcher.

But when Stamets enrolled in college, he still stuttered, and he still felt like a loner who would never fit in. One day he got hold of some psychedelic mushrooms and headed to nearby woods. He climbed a big tree, but was too intoxicated to climb back down. But that was the least of his problems, because he had an excellent view of storm clouds fast approaching the forest canopy.


The wind began to thrash the branches violently, and a bolt of lightning struck nearby. Stamets feared for his life, but he also felt an overwhelming connection to the world around him. Inspired by the intensity of his emotions, he asked himself whether he wanted to continue living the same isolated existence. It's time to stop stuttering, he told himself repeatedly.

After the storm was over and Stamets went home, his stutter had vanished. Eventually, he became a renowned mycologist (fungus expert), and his stutter never returned [source: Miller]. But he's one of the lucky ones. While childhood stuttering often disappears as person matures, it's extremely rare for adults — even young adults — to lose a stutter once it's established.

But what exactly is stuttering?


The Stuttering Spectrum

For most people who stutter, disfluencies begin and end during childhood. pixelheadphoto/iStock/Thinkstock

When someone speaks a language well, we often say that person is "fluent." "Fluent" is derived from the Latin word "fluere," which means "to flow." So, if speech is fluent, it flows uninterrupted.

A person who stutters experiences "disfluencies," or interruptions in the flow of speech. Of course, most people experience speech disfluencies to some degree or another — that's why we pause and say "um," "like" or various other verbal crutches. But for some people, these disfluencies are far more significant and can't be bridged by a word or phrase.


Disfluencies can take many different forms, including longer than normal pauses in speech; repeated words, phrases or letters; and most severely, complete blockage of speech. Often, people with stutters don't experience disfluencies all the time. Rather, certain situations (especially public speaking) can trigger stuttering. Many find various ways to disguise or hide their disfluencies with strategies that include rearranging the order of sentences, claiming to forget what they were saying or simply remaining mute. A stutter can also affect a person's choices in life, including profession. A person with a stutter might, for instance, decide against a life in politics and instead find work that requires little talking.

Roughly 1 percent of the global adult population stutters and, for reasons that remain unknown, men who stutter outnumber women 5 to 1 [sources: The Stuttering Foundation, NIDCD]. While some forms of stuttering can accompany a syndrome such as Parkinson's disease, and in some cases people acquire a stutter due to head trauma, the most common type of stuttering by far is developmental.

Typically, children who stutter begin to develop disfluencies between ages 2 and 4. About 5 percent of children stutter. Of that number, most (75 percent) will lose their disfluencies as they mature, but for some (the remaining 25 percent) the condition never really goes away. For the latter group, stuttering may have become a source of anxiety and negative self-image, making the problem continue as the disfluencies get locked into the developing brain, rather than fade away [sources: The Stuttering Foundation, NIDCD].

Recent research suggests that there might be genetic traits that predispose some people to stutter. If so, it appears that life experience is critical to triggering and reinforcing disfluencies.


What's Behind Stuttering?

Researchers have used brain scans to try to figure how stuttering develops. Nomadsoul1/iStock/Thinkstock

Speech is a very tricky process for humans. It originates in the parts of the brain dedicated to language processing, but is articulated by the motor system. Using brain-imaging technology, researchers discovered that stuttering seems to be linked to a discontinuity between the two processes. More specifically, they found overactivity in certain areas of the brain and underactivity in others.

There was, for instance, underactivity in the motor system but an overabundance of dopamine [source: Watkins]. Dopamine is a neurotransmitter, or chemical messenger that allows nerve cells to communicate, that vitally contributes to movement. Too little dopamine can result in clumsiness, while too much can cause tics and repetitive, unwanted movements [source: Mandal]. The neurotransmitter plays a role in other motor-control disorders, like Parkinson's and Tourette's.


What's unclear is whether the characteristics of stutterers' brains are congenital or developmental. In other words, are people born with a stutter, or does stuttering during a crucial period of brain development cause the structural abnormalities that the researchers found?

That hasn't been answered yet, although recent genetic research discovered four genes associated with some instances of stuttering. These four genes are linked to the proteins responsible for "cellular trafficking." This means the proteins are like ushers that ensure the elements of a cell end up in the right spots within that cell. It appears that more than one neurological disorder could be linked to problems with cellular trafficking [source: NIDCD]. It could be that some children experience stuttering in a relatively common developmental stage, but a subset of that group is genetically predisposed to continue stuttering into adulthood.

So, stuttering isn't a sign of stupidity. In fact, some studies indicate that kids who recover from stuttering tend to have more advanced language skills than their nonstuttering peers. One explanation could be that kids who begin to stutter in the typical window of development simply might be developing their language skills faster than their motor skills [source: Yairi].


Stuttering Through Time

According to the Bible, the prophet Moses had a stutter. Culture Club/Hulton Archive/Getty Images

Unsurprisingly, taking 'shrooms in a tree during a thunderstorm is not a recommended cure for stuttering, even though Paul Stamets swears by the medicinal properties of mushrooms. Still, it's probably no less potentially injurious than some of the recommended stutter-stemming techniques of the past.

Humans have probably stuttered for as long as we've been able to talk. Moses, for instance, is reputed in the Bible to have stuttered. The Talmud even has an explanation for how this happened. When Moses was a baby, the Pharaoh was told to be on guard against the tot because Moses was due to rebel when he grew up. So, in his wisdom, the Pharaoh decided to perform a little experiment with potentially mortal consequences. Baby Moses was to choose between a bowl full of shiny gold stuff and another one stuffed with hot coals. If Moses chose gold, he would die. Being a baby, of course, he reached for the shiny stuff. Luckily, an angel intervened and directed the infant's hand to the hot coals. Moses grabbed one and popped it in his mouth, thereby gaining a permanent stutter.


When Moses queried God about how he was to lead his people out of Egypt with a crippling stutter, God's answer was that Moses' brother, Aaron, would be Moses' spokesman. Sometime later another politician of the ancient world, the Greek statesman Demosthenes, enlisted a famous actor of his day to help ameliorate his disfluencies. The actor, Satyrus, had the politician perform various voice exercises with a mirror, speak with pebbles in his mouth and recite speeches while hiking uphill.

In sixth century Byzantium, Emperor Justinian's physician, Aetius of Amida, was one of the first to propose a surgical remedy, which involved slicing the frenulum (the thin flap of skin between your tongue and the floor of your mouth). Poor tongue! Variations of this remedy proved popular through the ages, as one doctor after the other came up with new ways of cutting that excellent muscle. In the 1830s, a French physician named H. de Chegoin was convinced that stutterers had oversized tongues. The obvious solution was to reduce, with the aid of a scalpel, the size.

Other treatments were less bloody. In the early 1800s, a Parisian doctor named Jean-Marc-Gaspard Itard favored the use of a small forklike object made of ivory or gold that he positioned under the tongue for support. While he claimed to have cured two people of stuttering, both eventually relapsed.

In the U.S., an intrepid pair named Jane Leigh and Christopher Yates developed an approach that was intended as a kind of strengthening, or reorientation, exercise. Once again, the tongue was assumed to be the culprit. Stutterers were to place the tip of their tongues hard against the front of their palates, directly behind the upper front teeth, and hold it there for three days.

So it went with each "specialist" claiming to have the solution so eagerly sought by stutterers down the ages.

And when psychoanalysis became the rage, it was a natural fit. Clearly, psychoanalysts said, stuttering was a neurosis [source: Goldberg]. What better cure for being unable to talk, than to talk?


Current Therapies

Speech therapist Lionel Logue treated King George VI's (shown here) stutter. Their relationship is depicted in the 2010 movie "The King's Speech." Lisa Sheridan/Studio Lisa/Hulton Archive/Getty Images

As mentioned earlier, 5 percent of kids go through a stuttering phase, and of that number, 75 percent outgrow the phase. So, when a kid begins to stutter, specialists recommend waiting at least three months to see if it lasts. If it does, they often suggest to parents a set of protocols to help their children in overcome disfluencies.

According to the NIH's National Institute on Deafness and Other Communication Disorders, the first step is to make sure kids have plenty of opportunities to talk, and that those aren't curtailed. Kids need to feel like they have room to express themselves. Additionally, speech pathologists often recommend that parents listen as patiently as they can to their kids, taking care not to interrupt them or finish their sentences if there are pauses or other disfluencies. Parents should also focus on what is being said, rather than the manner of expression. It's important that kids feel like they can communicate, even if they're stuttering. Accordingly, parents can slow down their own speech to let their kids know there's no rush to blurt everything out. And if a kid asks about stuttering, specialists recommend being as honest as possible about it, emphasizing that disfluencies are nothing to worry about.


The agency goes on to say that for those who continue to stutter into adolescence and adulthood, speech therapy can reduce disfluencies by helping them slow down their speech, control their breathing and retrain their speech patterns by starting with one-syllable utterances and slowly advancing to compound sentences. While early psychoanalytic practices often held that neurotic anxiety was at the root of stuttering, a more contemporary understanding is that stuttering itself can induce anxiety, which in turn makes the stuttering problem even worse. Pathologists teach strategies for managing this speech-related anxiety.

Currently, there is a movement to use specially conceived electronic devices to help people reduce their incidences of stuttering. One such device, which looks a bit like a hearing aid, changes the sound of the speaker's voice and replays it so that the speaker feels like he or she is talking in unison with somebody else. Electronic interventions help some stutterers overcome disfluency at a rapid pace.

Finally, the agency notes that many stutterers seem to do well in the forum of a support group, which can help people maintain ongoing self-study and deal with the challenges they face as a community.


Lots More Information

Author's Note: How Stuttering Works

When I was a kid, I didn't know anybody who stuttered. So, when I saw "A Fish Called Wanda," I thought Michael Palin's portrayal of the stuttering (or as the English say, "stammering") Ken was screamingly funny. But then my town hired a new manager, and when I went to the town hall to register to vote, I learned that he had a severe stutter. Seeing how difficult it was for him to talk made me realize that stuttering isn't really a source of comedy, and I've always been impressed by the courage it must have taken to work as a public servant with a stutter.

Related Articles

More Great Links

  • American Speech-Language-Hearing Association. "Stuttering." (Jan. 16, 2017)
  • Goldberg, Barbara. "Historic Treatments for Stuttering: From Pebbles to Psychoanalysis." ASHA. Pg. 71. June-July 1989.
  • Mandal, Dr. Ananya. "Dopamine Functions." News Medical Life Sciences. Oct. 27, 2015. (Jan. 22, 2017)
  • Miller, Kenneth. "How Mushrooms Can Save the World." Discover Magazine. May 31, 2013. (Jan. 20, 2017)
  • National Institute on Deafness and Other Communication Disorders (NIDCD). "Results of Brain Imaging May Help Explain Why More Men Than Women Stutter." NIDCD Newsletter. Winter 2011. (Jane. 23, 2017)
  • National Institute on Deafness and Other Communication Disorders (NIDCD). "Stuttering." (Jan. 21, 2017)
  • Ridley, Matt. "Hands and Faces Spoke Long Before Our Tongues." Wall Street Journal. Feb. 26, 2011. (Jan. 20, 2017)
  • Snyder, Greg. "The Existence of Stuttering in Sign Language and other Forms of Expressive Communication." Minnesota State University. 2006. (Jan. 20, 2017)
  • The Stuttering Foundation. "FAQ." (Jan. 22, 2017)
  • Watkins, Kate E. et al. "Structural and functional abnormalities of the motor system in developmental stuttering." Brain. Vol. 131, pt. 1. Pp. 50-59. Jan. 2008. (Jan. 20, 2017)
  • Yairi, Ehud. "Is Language a Risk Factor in Stuttering?" The Stuttering Foundation. 2006. (Feb. 14, 2017)