Overview of Nonverbal Autism

Little girl standing near the stairs.

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An estimated one-third of people diagnosed with autism spectrum disorder are considered nonverbal, meaning that they'll never learn to speak more than a few words. Even so, nonverbal autism is poorly researched, and little is known about the thought processes of people who don't speak.

Some research is ongoing, though, and new technologies are opening doors of communication and understanding.

What Is Nonverbal Autism?

Despite the prevalence of autistic people who don't speak, the term "nonverbal autism" has no official status, and there is no such diagnosis as "nonverbal autism." In part, that's because there is no clear line between verbal and nonverbal individuals with autism.

For example, some people with nonverbal autism do develop the ability to use a few words in a meaningful manner but are unable to carry on any kind of significant conversation. For example, they may say "car" to mean "let's go for a ride," but would not be able to answer the question "where should we go?"

Some have the ability to speak but lack the ability to use language in a meaningful way. They may "echo" scripts from television or expressions they've been taught by therapists. Instead of using these scripts to communicate ideas or desires, however, they seem to use "scripting" as a form of self-calming stimulation.

Quite a few nonverbal individuals can't use spoken language effectively but are able to communicate with written or typed language, American sign language, picture cards, or digital communication devices. Once an individual is effectively communicating, even without spoken language, their ability to engage in the world expands dramatically.

Intelligence and Lack of Speech

Anyone who receives an IQ score of 70 or less on specific tests is labeled Intellectually Disabled (ID). Until relatively recently, it was assumed that all nonverbal children with autism were intellectually disabled for the simple reason that their IQ scores fell under (often far under) 70.

It's recently become clear that typical IQ tests are very poor tools for measuring intellectual ability in children with autism—particularly when those children are nonverbal. The reasons are fairly obvious; for example:

  • IQ tests, for the most part, depend upon the test taker's ability to quickly understand and respond to verbal information. Nonverbal children with autism obviously have challenges in those areas that may or may not have any connection to basic intelligence.
  • Most IQ tests require an ability to understand and respond to social norms and expectations, and to respond within a specific period of time. These expectations are very challenging to kids with autism, whether verbal or not.
  • Sensory issues that don't cause issues for typical children may distract children with autism. Nonverbal children with autism don't have the ability to let testers know about such issues.
  • Testers are rarely trained to work with, engage with, or "read" children with special needs, especially children who are nonverbal. If they can't engage the child, it is very unlikely that the child will present their highest level of ability. 

How, then, should IQ be measured among nonverbal children with autism? Ideally, the answer should include both nonverbal IQ tests and non-test-related observations. 

The TONI (Test of Nonverbal Intelligence) is one example of a nonverbal IQ test that is usually a better option for nonverbal children and for children with autism in general. Observation of nonverbal children in familiar settings can also provide evaluators with real-world information about abilities versus test-taking skills.

Often, while nonverbal autistic children may fail to cooperate with or fully grasp the intent of standardized tests, they are quite capable of handling intellectual challenges, such as solving complex math problems or puzzles.

Of course, neither school districts nor agencies are likely to accept the outcomes of these evaluations anytime soon, but research suggests that they are much more likely to reveal a child's true potential.

Why Don't They Learn to Talk?

One of the strangest aspects of nonverbal autism is the fact that no one really knows why some people with autism can't, or don't, use spoken language. It is especially puzzling because quite a few nonverbal people on the spectrum can and do choose to communicate using American Sign Language, picture cards, and a range of digital tools.

Some people with autism also have childhood apraxia of speech, a neurological disorder that makes spoken language extremely difficult. But most nonverbal individuals on the autism spectrum don't have apraxia; they just don't speak.

Clearly, there are differences in brain function that inhibit spoken language, but at this point, there is no agreement on just what those differences are or how they impact any given individual.

Studies are making use of instruments such as electroencephalograms (to measure brainwaves) and MRIs (to measure brain activity) in an effort to better understand what is going on inside the mind of a person who does not or cannot talk. Others are measuring eye gaze.

So far it seems clear that people with non-verbal autism understand much more than they communicate; but how much more, and at what level, remains unclear.

Will My Child Learn to Talk?

Very often, therapists use the term "preverbal" rather than "nonverbal" to describe autistic children who do not use spoken language. Quite a few autistic children with delayed speech gain the ability to communicate with spoken language. Some become quite fluent. Others, however, never gain more than a few words, if that.

According to an NIH Workshop publication on Nonverbal School-Aged Children with Autism, "...it is a very significant challenge to assess these individuals with traditional standardized instruments. Our current measurement tools have relatively low reliability and validity for this population.

"The presence of even one word, or some echolalic speech, appears to be a significant predictor for the acquisition of spoken language after 5 years of age.

"In both research and treatment planning, it is important to distinguish whether children are nonverbal (i.e., no spoken language), preverbal (i.e., younger children who have not yet developed verbal language), or non-communicative (i.e., having neither verbal nor nonverbal communication skills)."

Encouraging Your Child to Speak

There are many techniques for encouraging and improving spoken language for children with autism, though there is no guarantee that any particular approach will be effective for any given child.

Research suggests several different approaches can improve verbal communication, including:

If your child isn't speaking or using words to communicate, it's important to remember these surprising and important facts:

  • Late language acquisition is not necessarily an indication of low IQ or poor prognosis.
  • Children with autism may develop language much later than typically developing children, which means that it is worthwhile to continue speech therapy.
  • Communication using non-verbal techniques (PECS picture cards, sign language, etc.) can be very important in establishing communication. Children who build communication skills using these techniques often gain spoken language skills at the same time.
  • It is well worth parents' time, money, and energy to invest in digital pads, apps, and software that allow their child to communicate by tapping on images (or, in some cases, on keyboards). 

A Word From Verywell

While there are a number of great tools for encouraging speech and communication, it's important to steer clear of hoaxes that sound too good to be true. In the world of autism, one of these potential pitfalls is "facilitated communication," in which a therapist "supports" the arm of an autistic person while he or she types.

This approach is still available but has been debunked by numerous studies that show that it is the therapist, and not the autistic person, who is guiding the typing finger.

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Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  3. National Institute on Deafness and Other Communication Disorders. NIH workshop on nonverbal school-aged children with autism. Updated July 21, 2015.

  4. Centers for Disease Control and Prevention. Treatment for autism spectrum disorder. Updated August 26, 2019.

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  6. Sharda M, Tuerk C, Chowdhury R, et al. Music improves social communication and auditory-motor connectivity in children with autism. Transl Psychiatry. 2018;8(1):231. doi:10.1038/s41398-018-0287-3

Additional Reading
  • RudacilDeborah. IQ scores not a good measure of function in autism. Spectrum News, 6 January 2011.
  • Berdick, Chris. Cracking the code of silence in children with autism who barely speak. Boston University website. July 2015. 

  • Bardikoff, N. et al. Testing nonverbal IQ in children with Autism Spectrum Disorders.Research in Autism Spectrum Disorders. Volume 8, Issue 9, September 2014, Pages 1200–1207
  • National Institute on Deafness and Other Communication Disorders. NIH Workshop on Nonverbal School-Aged Children with Autism. April 2010.