Why Are Some Autistic People Nonverbal?

About 30% of autistic people in the U.S. are nonverbal or nonspeaking. There haven’t been enough studies to figure out the reasons for this, but there are likely several different causes.

Some people with autism may have an intellectual disability that affects their ability to speak—but that isn’t true for everyone. Just because a person doesn’t speak doesn’t mean they have an intellectual disability. There could be other things going on in the brain that affect communication. We’ll take a look below.

One thing that is certain: Autistic people should receive supports they desire that can help them effectively communicate.

Defining ‘Nonverbal’

“Nonverbal” or “nonspeaking” can be a bit misleading. Researchers generally use these terms to refer to “individuals who are severely language delayed and do not produce functional spoken language,” explained neuropsychologist Elgiz Sener, PhD, assistant clinical director at the Center for Autism Services, Science and Innovation at Kennedy Krieger in Baltimore. She is also an assistant professor in the Department of Psychiatry and Behavioral Sciences at Johns Hopkins School of Medicine.

Some nonverbal people may occasionally say words or phrases, but the words may not mean anything in the moment.

“They might engage in ‘echolalia,’ meaning that they repeat back words, phrases or sentences right after they’ve heard them or at a later time, which is referred to as ‘delayed echolalia’. This repetition can serve multiple purposes, including processing language, self-regulation or communication,” said Christine Cukar-Capizzi, PsyD, a licensed clinical psychologist and licensed behavior analyst who specializes in the assessment and treatment of autism. She is also an assistant professor of clinical child psychology at the Yale Child Study Center at the Yale School of Medicine in Connecticut.

“Or, they may use some language that we refer to as ‘scripted language,’ where individuals might repeat phrases or lines they’ve heard from favorite shows, movies, commercials or books they’ve read,” Dr. Cukar-Capizzi explained. This type of language may seem unusual because it may be out of context to the situation.

In addition, some autistic people do speak but are “minimally verbal,” which is described in some studies as 20 novel or spontaneous words during a 20-minute period, Dr. Sener said.

“With minimally verbal individuals, the overall rate of spoken language is usually very low, and any speech that is present may include highly practiced or scripted phrases,” she said.

Some autistic people understand words and communication, even if they don’t speak. In fact, some autistic individuals prefer the term “nonspeaking” because it better explains that while they are not speaking, they may still be able to “receive” or understand language.

“Comprehension and expression are different skills,” Dr. Sener said. “Sometimes they may understand far more than they are able to speak and communicate.”

Research of ‘Nonverbal’ Causes

There is not one single answer to explain why some autistic people are nonspeaking or nonverbal. “Despite speech-language interventions or other therapies, some children don’t make progress in acquiring language,” Dr. Sener said. “What we know is that this group is very variable.”

Let’s look at some of the possibilities. Cognitive delays or intellectual disabilities may affect a child’s ability to develop expressive language, according to Dr. Sener. About 40% of autistic kids do have an intellectual disability, and that may or may not affect their ability to speak, she said.

But that leaves about 60% who do not have an intellectual disability—showing that we cannot assume that because someone is autistic and nonverbal that they have an intellectual disability.

Some kids may have apraxia of speech, or childhood apraxia of speech, which is a rare speech disorder in which kids have trouble moving their lips, jaws and tongues when speaking. Apraxia of speech is a brain disorder in which there is a problem with the pathways that tell parts of the mouth how to move to form speech.

Some research has shown that higher levels of sensory hyporesponsiveness—in which people have a reduced reaction to sensory stimuli such as noise, touch, facial expressions and more—might be associated with being nonverbal.

Some autistic nonspeaking people have said, through alternative communication methods, that they don’t speak because verbal communication is more challenging or uncomfortable.

And still, other research of autistic children has shown delayed auditory processing (the ability to understand what you are hearing) in the brain.

Not a lot of research exists on nonverbal autistic people partly because it’s more challenging for researchers to develop such studies or to communicate with participants. In addition, brain imaging studies might use an MRI, which can be noisy and scary.

A 2019 study by researchers at the Children’s Hospital of Philadelphia Intellectual and Developmental Disabilities Research Center used magnetoencephalography, a noninvasive, safe and silent brain imaging tool to study the brains of nonverbal or minimally verbal autistic children.

The study enrolled 16 minimally verbal or nonverbal children with autism, as well as 55 verbal children with autism and 34 neurotypical children to serve as a control group. All children were ages 8 to 12.

The researchers found that the minimally verbal or nonverbal participants had delayed M50 latency and delayed M100 latency— which means they had slower early processing and slower secondary processing in the brain when responding to simple auditory tones. These longer response times were associated with poorer communication skills, which were measured by a standardized questionnaire completed by parents.

But the reason for these delays in the brain is unclear, the researchers said. They speculated whether there was a delay in the development of the auditory cortex—which happens between 6 months old and age 5 and continues to mature until age 12—or whether there were some abnormalities in the brain’s thalamus, which plays a key role in processing information from all our senses.

The risk of autism is likely formed in a person’s genes. In fact, genetic mutations have been discovered for some rare forms of autism. Perhaps verbal ability is also affected by genetic factors. (“Risk” doesn’t guarantee someone will have that condition or disease.)

A 2025 study examined genetic factors contributing to nonverbal status in autistic people. The researchers identified a common variant in the genome called CNTN5 that was significantly associated with nonverbal status. CNTN5 has roles in helping brain cells connect with each other. The study also found that children with a higher autism‑related genetic risk were significantly more likely to be nonverbal.

Communication for Nonspeaking People

There are many methods and tools available to help nonspeaking children and adults communicate, especially with advances in technology. These often fall under the umbrella term “augmentative and alternative communication,” or AAC, methods. AAC methods can include sign language, gestures, picture communication boards, an iPad or tablet, and speech-generating devices.

AAC “encompasses a variety of techniques and tools that we use to help a person express their wants and needs, feelings and ideas,” said Melissa Subock, MS, manager of speech-language pathology clinical services at the Center for Autism Services, Science and Innovation at Kennedy Krieger in Baltimore.

An assessment by a neuropsychologist or other expert can help identify an autistic individual’s strengths, areas of need and intellectual ability. An assessment by a speech-language pathologist can assess a child’s receptive and expressive language, social communication, speech production and more.

These assessments can then help clinicians and parents or caregivers begin to develop AAC methods that work best for that individual. AAC may be used as a person’s primary means of communication. But some may also use it in specific situations, maybe in social settings where they feel more uncomfortable or to better explain themselves when there’s a communication breakdown, Subock said.

If a child has not developed fluent verbal communication by approximately age 7, the likelihood that they will need an AAC to communicate is greater, Subock said. “While there may be an increased likelihood a person will need long-term supports, we do not recommend waiting to provide AAC to patients who may benefit,” she said. “We seek to introduce AAC as soon as we identify there is a need, ideally prior to or during a child’s preschool years.”

AAC methods “can help really decrease that frustration because they’re better able to meet their communication needs,” she continued. And, she emphasized, research has shown that the use of AAC tools does not hinder speech development—meaning children who use AAC devices may still be able to develop or improve their speaking or verbal communication.

Providing nonspeaking autistic children and adults ways to communicate can be life-changing, Dr. Cukar-Capizzi said. “Anytime that we’re able to give someone access to an alternate mode of communicating, it can reduce frustration and support their ability to express their needs, wants and preferences.”

Autistic Nonspeaking Adult Publishes Debut Novel

Woody Brown, an autistic nonspeaking young adult, published his first novel this year. The book highlights an autistic community and calls attention to misunderstandings and prejudices they face.

In 2022, Brown became the first autistic nonspeaking graduate of University of California, Los Angeles (UCLA), according to People magazine. He went on to receive a master’s degree in creative writing at Columbia University.

Brown’s book, Upward Bound, was published on March 31, 2026. It tells the story of clients and staff at an adult daycare center for Los Angeles’s disabled community.

As part of his creative writing thesis at UCLA, Brown wrote a series of short stories that included a fictional tale of a nonspeaking autistic adult, according to a UCLA College article. As the article quotes, Brown’s character tells readers, “As much as I wish I could just type my thoughts independently, that’s not how it works for most nonspeaking spellers. Our brains have trouble getting all the motor planning lined up to perform the complex actions involved in typed communication. Most people don’t even consider how many parts of the brain are activated when they speak or type. If your electronic impulses resist firing in the right order, like mine do […], the message gets lost somewhere between the thought and the finger hitting the keyboard.”

Read more about Brown and his debut novel in The New York Times.