If you are reading this, there is a reasonable chance you spent part of today trying to work out what your child wanted. Food, drink, tired, too loud, tag in the shirt, and you never landed on it. That is an exhausting kind of helplessness, and it is worth naming, because most articles on this subject go straight to technique without acknowledging how much of your day it takes.
Here is the good news, and it is real. Being understood does not require speech. It requires a method, any method, that works reliably and that your child can reach for when it counts. That is functional communication, and it is among the most thoroughly researched areas in autism intervention. What follows is what it is, why so much difficult behaviour turns out to be communication in disguise, the forms it can take, what the research says about the fear that keeps most parents up at night, and how the teaching sequence works.
The essentials, up front
- Communication and speech are not the same thing, and the goal is a child who can be understood, not one who sounds a particular way.
- Most challenging behaviour is already communication. It persists because it works and because nothing easier exists yet.
- A gesture, a sign, a picture card, and an app are all valid routes, and the right one is whichever your child can use fastest.
- Using pictures or a device does not delay speech. The research points the other way.
- A replacement only sticks if it beats the old behaviour on speed and reliability, which means honouring it almost every time at the start.
- Progress usually shows up first as fewer meltdowns rather than more words, and that counts.
Quick Answer: What is functional communication for autistic children?
Functional communication is any reliable way a child can express a want, a need, a refusal, or a feeling and have it understood and acted on. It includes speech, but also gestures, sign, picture exchange, and speech-generating apps. The aim is not a particular form but a functional one: something your child can use quickly, in the moment, with the people around them. The structured method for teaching it, functional communication training, was first described by Carr and Durand in 1985 and is now recognised as an evidence-based practice for autistic children.
Communication is the goal. Speech is one route to it.
This sounds academic until you see what it changes in practice. When speech is the target, a child with no words has nothing to use for months or years while they work toward it. When communication is the target, that child can have a working method this month, with speech developing alongside it rather than instead of it.
Current estimates suggest around 25 to 30 percent of autistic children do not develop functional speech and remain minimally verbal beyond the age of five. For those families, waiting for speech before providing a method is not a neutral choice. It is years without a way to ask.
Minimally verbal also does not mean not understanding. The American Speech-Language-Hearing Association lists the assumption that nonspeaking autistic people have intellectual disability among the misconceptions it formally corrects. Comprehension and expression sit at very different levels in many children, which is why a child who clearly understands everything can still have no way to tell you what hurts.
Most difficult behaviour is already communication
This is the reframe that changes how a household feels. Behaviour that looks like defiance almost always has a job, usually one of four: getting access to something, escaping something, getting attention, or meeting a sensory need. It continues because it accomplishes that, and because every easier option has failed or does not exist.
Seen that way, a child who screams when the tablet goes away is not being difficult. They are using the only method that has ever worked for protesting. The screaming is not the problem. The absence of an alternative is.
Which is why the first step is never a strategy; it is an assessment. A functional behaviour assessment works out what a specific behaviour accomplishes for a specific child, because the replacement has to serve that same purpose. Teaching a child to ask for a break will not touch a behaviour that was really about wanting attention. Functional communication training always begins there, as the Association for Science in Autism Treatment sets out, and skipping it is the most common reason home attempts fail.
The forms it can take
There is no hierarchy here, and no form is a lesser version of speech. The only question is which one your child can use most easily right now. Many children use several at once.
| Form | What it looks like | Often suits | Worth knowing |
|---|---|---|---|
| Gestures and pointing | Reaching, pointing, leading you by the hand, pushing something away | Very early communicators, and a fast first win | Already in most children's repertoire, so often the quickest thing to strengthen |
| Word approximations | "Buh" for bubbles, consistent sounds that are not full words | Children with some vocal output | Accept and reinforce the approximation rather than holding out for the clear word |
| Key word signing | A small set of signs for high-value items, not full sign language | Children with good motor imitation | Always available with nothing to lose, but only works with people who know the signs |
| Picture exchange | Handing over a photo or symbol card to make a request | Children who find motor imitation hard | Concrete and portable, though you have to carry the right cards |
| Speech generating app | Tapping symbols on a tablet app that speaks the word aloud | Children ready for a larger vocabulary | Understood by anyone and grows with the child, but needs charging and setup |
| Written or typed words | Typing, spelling, selecting written words | Literate children and many older ones | Powerful where it fits, but requires literacy to already be in place |
Starting with pictures or a device does not lock a child into it. Children move between forms constantly, and the direction of travel is usually toward more communication.
"Will a device stop my child from learning to talk?"
This is the question I get asked most, often quietly, at the end of a conversation about something else. It deserves a direct answer: no. The research does not support that fear, and it has been examined repeatedly.
A research review by Millar, Light, and Schlosser in the Journal of Speech, Language, and Hearing Research in 2006 examined speech production before, during, and after augmentative and alternative communication intervention and concluded these interventions do not inhibit speech. A systematic review by Schlosser and Wendt in the American Journal of Speech-Language Pathology in 2008 focused on autistic children specifically and agreed, finding most studies reported an increase in speech production, though the authors called those gains modest. ASHA's guidance reflects this, stating that augmentative and alternative communication "can enhance independent communication and often supports the development of speech for autistic people."
It makes sense once you sit with it. A child with a reliable way to request gets far more successful communication practice per day, hears the word modelled back every time the device speaks it, and spends less energy on distress. That does not compete with speech; it feeds it. The limits are worth stating plainly: this is a modest research base, and no study can promise your individual child will speak. What it does say clearly is that giving your child a method now does not cost them one later.
How the teaching actually works
Your child's BCBA runs the assessment and sets the targets, but knowing the shape of the plan helps you see what is happening and why.
- Work out the function first. What is the behaviour achieving? Everything downstream depends on this.
- Pick a form your child can already produce, or nearly. A replacement harder than the behaviour it replaces will lose. If handing over a card takes four seconds and screaming takes one, screaming is still the better deal.
- Make it unmistakably effective. In the early weeks, the new request should work almost every time, immediately. This feels indulgent to a lot of parents, and it is the most important part. You are not spoiling your child; you are proving the new method is more reliable than the old one.
- Keep it available. A card in a drawer in another room is not a communication system. It has to be within arm's reach when it is needed, which means duplicates around the house and one on you.
- Then build complexity. Once the request is solid, add waiting, add "after dinner" rather than "right now", expand vocabulary, and teach it with new people and places. This is where assent-based practice matters most, because a child learning that their requests get honoured is learning something bigger than a skill. They are learning that communicating with you is worth doing.
What this looked like in one family
In our sessions we see this arc often enough that I can describe it almost as a template, though I have blended details across several families so nobody is identifiable.
A four-year-old boy, no reliable words, and a pattern his parents described as going from fine to screaming with nothing in between. The assessment turned up something they had not expected: the flashpoints clustered around food, specifically food he could see but could not name. He was handed a plate with no way to say which part of it he wanted.
We started with two picture cards. Not a full board, two. One for more, one for finished. His mum kept duplicates on the fridge, in the car and in her bag, and for the first fortnight we honoured both essentially every time, including when it was inconvenient.
Three weeks in, the mealtime screaming had largely stopped. By week seven he had around fifteen cards and was combining two. In week nine his dad called to say he had said "muh" while handing over the more card, which is the pattern the research describes: the card did not replace the word, it made room for it. His parents found that first fortnight hardest. What they talk about now is that he stopped screaming at dinner.
What tends to get in the way
- Testing the child. Holding up a card and asking "what do you want?" when you already know turns communication into a quiz. Set up real reasons to ask instead.
- Honouring it only sometimes. Intermittent success teaches a child that the new method is unreliable and the old one is not.
- Starting too big. A forty-symbol board on day one overwhelms everyone. Two or three high-value items first.
- Dropping it when behaviour spikes. A behaviour that used to work often gets louder before it fades. That spike is usually evidence the plan is working, but tell your BCBA so they can confirm it.
- Treating speech as the only success. If your child can tell you what they need and the household is calmer, that is the outcome. Words may follow, and they are a bonus rather than the scoreboard.
Where to go from here
The thread running through all of this is simple. Your child is already communicating. The work is giving them a route that is faster and more reliable than the one they have had to invent, then proving in those first few weeks that it works. Speech may well come. Being understood is the thing that changes your Tuesday afternoon.
At Centerbrite, this is a large part of what we do. Our BCBAs assess what a behaviour is accomplishing before proposing a replacement, choose a form matching what your child can already produce, and build the plan into your home routines rather than a clinic room. Because our sessions are play-based and assent-driven, honouring your child's requests is the method rather than a concession, and parent training and coaching is in every plan from the start, so the system works at 6 pm on a Sunday and not only when a therapist is present. We provide in-home ABA therapy across New Jersey and Virginia.
If you spent part of today guessing at what your child needed, you do not have to keep guessing. Contact us today, and we will talk about what a first communication method could look like for your child.
Frequently Asked Questions
1. My child can talk, so is this relevant to us?
Often yes. Plenty of speaking autistic children lose access to their words under stress, exactly when they most need to communicate. A backup method for those moments, plus explicit teaching of how to refuse or ask for a break, is frequently the missing piece for verbal children whose hard moments seem to come from nowhere.
2. How long before we see something change?
With a correctly identified function and a form the child can already produce, many families see the first reliable request within two to four weeks, with the behaviour it replaces easing shortly after. Broader vocabulary and using it with new people takes months, and that is normal rather than slow.
3. Does my child have to be a certain age or level to start?
No, and waiting is rarely the right call. There is no prerequisite skill set, because the form is chosen to match what your child can already do. The National Clearinghouse on Autism Evidence and Practice reviewed 972 studies from 1990 to 2017 and identified 28 evidence-based practices for autistic children and young people, with both functional communication training and augmentative and alternative communication among them.
4. Is this just about stopping behaviour we find difficult?
It should not be, and if it is framed that way, push back. The goal is your child having agency and being understood. A plan built around adult convenience teaches compliance rather than communication, and it does not hold, because a child who learns that communicating gets them nowhere stops communicating.
Sources:
- https://digitalcommons.usf.edu/fac_publications/1194/
- https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2025.1549092/full
- https://www.asha.org/practice/autism-and-communication-skills-misconceptions-versus-facts/
- https://asatonline.org/for-parents/learn-more-about-specific-treatments/applied-behavior-analysis-aba/aba-techniques/functional-communication-training-fct/
- https://ncaep.fpg.unc.edu/wp-content/uploads/EBP-Executive-Summary_Accessible.pdf
