Functional Communication Training: Replacing Behaviors With Words

When a child screams, drops to the floor, or hits, it is easy to feel like the behavior comes out of nowhere. But almost every challenging behavior is your child trying to tell you something. Functional communication training (FCT) is the ABA approach that teaches a child to send that same message with a word, sign, or picture instead.

FCT is one of the most studied and trusted tools in autism intervention. Instead of simply trying to stop a behavior, it asks a kinder, smarter question: what is my child trying to say, and how can I teach an easier way to say it? This guide walks New Jersey parents through what FCT is, why it works, and how it might look for your child at home.

Behavior Is Communication

Long before children have words, they communicate with their bodies. A baby cries to be picked up; a toddler points at the cookie jar. For many autistic children, spoken language comes slowly or unevenly, but the need to communicate is still there. When the easiest available tool is a meltdown or grabbing, that is what a child will use, because in the past it worked.

This is the core insight behind functional communication training: challenging behavior usually serves a purpose, or function. Researchers generally describe four common functions:

• To get something — a toy, food, a favorite video, a turn.
• To get attention — a hug, help, or simply for someone to look up and notice.
• To escape or avoid — a hard task, a loud room, an unwanted transition.
• For sensory reasons — the behavior itself feels good or soothing.

Once you know why a behavior happens, you can teach a replacement that meets the same need. The goal is never to silence a child — it is to give them a faster, gentler way to be understood.

What Functional Communication Training Actually Is

Functional communication training was first described in 1985 by researchers Edward Carr and V. Mark Durand, who showed that when children were taught to request attention or help directly, their tantrums, aggression, and self-injury dropped sharply. Decades of single-case studies since then have made FCT a well-established, evidence-based practice recognized by the National Clearinghouse on Autism Evidence and Practice.

In plain terms, FCT does two things at once. It teaches a new communicative response that is just as effective as the old behavior, and it makes sure that new response reliably gets the child what they want. A child who used to bite to escape a hard worksheet might be taught to hand over a 'break' card or sign 'all done.' When the break card works every time and biting no longer does, the child naturally shifts to the easier, safer option.

FCT is a close cousin of teaching requesting skills, or manding, and it leans on the same engine as most ABA: positive reinforcement. The difference is that FCT specifically targets a behavior you want to reduce and pairs the new skill with a thoughtful plan to stop reinforcing the old one.

It Starts With a Functional Behavior Assessment

You cannot teach the right replacement until you understand the message. That is why FCT almost always begins with a functional behavior assessment (FBA), conducted by a Board Certified Behavior Analyst (BCBA).

During an FBA, the BCBA gathers information through interviews, direct observation, and data on what happens right before and right after the behavior. They are looking for patterns: Does the screaming happen mostly at clean-up time? Does the hitting appear when a sibling gets attention? These clues reveal the function.

Getting the function right matters enormously. If a child hits to escape a task, but the team mistakenly teaches them to ask for a snack, the new skill will not stick — because it does not meet the real need. A careful assessment is what keeps FCT honest and effective. You can read more about how this discovery process works in our overview of functional behavior assessments.

Choosing the Right Communication Response

One of the most important decisions in FCT is how the child will communicate. The best response is one your child can produce easily, quickly, and almost anywhere. It does not have to be spoken words. Common options include:

• Spoken words or word approximations — 'help,' 'more,' 'break,' 'no.'
• Sign language or simple gestures — useful when speech is still emerging.
• Picture exchange — handing over a card, as in the PECS system.
• Speech-generating devices or apps — part of the broader world of augmentative and alternative communication (AAC).

A good rule of thumb: the new response should take less effort than the challenging behavior. If asking for a break is harder than throwing the materials, your child will keep throwing. The team also makes sure the response is something other people will recognize and honor — a teacher, a grandparent, a babysitter. A sign only helps if the people around your child understand it, which is why a picture card or device sometimes wins out: anyone can read it.

It is also worth saying clearly that giving a child a picture card or AAC device never holds back their speech. Research and clinical experience consistently show the opposite — reducing the frustration of not being understood often frees a child up to develop spoken language, not replace it. FCT meets your child where they are today and grows with them. For children who are not yet speaking, our guides on communicating with a nonverbal child and choosing an AAC device can help you weigh the options.

How FCT Looks in a Real Session

FCT can sound technical, but in practice it is built on small, repeated moments. Here is how a typical sequence unfolds:

• Set up the situation. The therapist or parent arranges a moment where the child is likely to want something — placing a favorite toy just out of reach, for example.
• Prompt the new response. Before frustration builds, the adult gently prompts the child to use the target communication, such as signing 'more' or tapping a picture.
• Reinforce immediately. The instant the child communicates, they get exactly what they asked for. Fast, consistent payoff is what makes the new skill worth using.
• Fade the prompts. Over time, the adult offers less help, so the child initiates on their own.
• Stretch and generalize. Gradually, the child learns to wait a moment, to ask in new places, and to handle a calm 'not right now.'

Imagine a four-year-old who screams and throws toys at clean-up time because the activity is ending. Through FCT, the team might teach 'one more' — a phrase, sign, or card the child can use to request a final turn. At first the adult prompts 'one more' the instant clean-up begins and grants it immediately, so the child learns the new phrase works. Over weeks, the team fades the prompt, then gently teaches the child to accept 'all done' after that last turn. The screaming fades not because it was punished, but because a calmer message became the more reliable way to be heard.

That last step — learning to tolerate a delay or a 'no' — is part of why FCT pairs so naturally with other skills, like handling transitions and building flexibility. The communication response opens the door; the tolerance skills keep it from slamming shut when the answer is not an instant yes.

Because in-home therapy happens in the rooms where real life unfolds — the kitchen at snack time, the doorway at transitions — it is a natural fit for FCT. This overlaps with natural environment teaching, where skills are practiced inside everyday routines rather than only at a table. You can see how our team builds these plans on our services page.

Why Parents Are the Key Ingredient

FCT only works if the new response pays off consistently — and that means everyone in the child's life has to be on the same page. If a 'break' card earns a break with the therapist but gets ignored at bedtime, the behavior plan unravels.

This is why the parent role in ABA is so central. Your BCBA will coach you to recognize the early signal, prompt the replacement, and honor it quickly. It can feel like a lot at first, especially during the stretch when an old behavior briefly flares up before the new one takes hold. That spike is common and usually temporary, and your team will prepare you for it.

A few things that help families succeed:

• Keep the communication tool (cards, device, sign list) visible and within reach.
• Respond to the new response every single time at first, even when it is inconvenient.
• Share the plan with grandparents, siblings, and teachers so the message is honored everywhere.
• Celebrate small wins — the first unprompted 'help' is a milestone.

Getting Started in New Jersey

If meltdowns, aggression, or self-injury are part of your daily life, you do not have to manage it alone. FCT is delivered by a BCBA-led team, and in New Jersey it is typically covered through private insurance under the state's autism insurance mandate, as well as through NJ FamilyCare (Medicaid). Our guides on insurance coverage for ABA in NJ and how to start ABA therapy walk you through the steps.

Autumn ABA provides in-home ABA therapy across all 21 New Jersey counties, so a child can learn to communicate in the exact settings where challenging behavior shows up. You can confirm coverage in your area on our locations page, browse more family guides in our resource library, or reach out directly when you are ready to get started. Our office is at 5 Professional Cir, Colts Neck, NJ 07722, and you can call us at 732-664-0038.

Frequently asked questions

Helpful resources & references

• Carr & Durand (1985), Reducing behavior problems through functional communication training (PMC)
• AFIRM, Functional Communication Training Brief Packet (University of North Carolina, FPG Child Development Institute)
• National Professional Development Center on Autism, FCT Evidence-Based Practice Brief (ERIC)
• Autism New Jersey, Introduction to Applied Behavior Analysis
• A Meta-Analysis of Functional Communication Training for Young Children with ASD in Natural Settings (PMC)