Functional Communication Training (FCT): A Practical Guide

Functional communication training teaches a person a better way to ask for what they want. We call this a functional communication response, or FCR. It is a simple request that replaces a harder behavior. The person learns to ask instead of hit, scream, or run.

This matters because behavior almost always has a reason behind it. That reason is called the function. When a child screams, they may want a break or a toy. FCT gives them a clear way to say that. It helps BCBAs, RBTs, and parents lower hard behavior while building real communication skills.

What functional communication training actually is#

FCT starts with one honest question. What is the behavior trying to get? You cannot pick a good replacement until you know the reason. So FCT depends on a functional behavior assessment, which is a check that finds the reason behind the behavior.

Once you know the function, you teach a matching request. If the child wants a break, you teach them to ask for a break. If they want a toy, you teach them to ask for it. Then you make sure the request works and the old behavior does not.

Matt Harrington calls FCT the foundation of the whole field.

FCT is the biggest intervention in behavior analysis. Like, I don't think it's arguably. I think it is. From the talk — Matt Harrington

Why FCT works so well#

FCT is powerful because of a simple math idea. The request gets rewarded almost every time. The hard behavior stops getting rewarded. This gap is what drives change.

Matt Harrington teaches this as contingency strength. That is just how reliably a behavior gets a payoff. The request has a high payoff. The severe behavior has a very low one. The bigger that gap, the faster behavior improves.

Done the classic way, FCT has two parts. You reward the request every single time. You stop rewarding the hard behavior, which is called extinction. Matt notes you can even reach the same effect without putting the severe behavior on extinction directly. You can extinguish a smaller warning behavior and reward the request instead.

The request must work for strangers#

A request only helps if other people understand it. That is the heart of social validity, which means the skill works in real life. FCT was built with this goal in mind.

Matt Harrington uses a simple test for every new request he teaches.

And I always try to ask myself, when I'm doing a functional communication training setup, could a substitute teacher reinforce this mand if they had no notes left for them by the primary education teacher? From the talk — Matt Harrington

This test keeps the skill useful. The child should be able to enter a new room and still be understood. The goal is not a private code that only the trained team can read. The goal is real communication that travels with the person.

Flexible requests for complex profiles#

One rigid request does not fit every learner. Some children, like those with a demand-avoidant profile, push back on strict rules. Asking for one exact phrase can feel like a brand new demand. That can make things worse, not better.

B. Kuerine Gray suggests accepting several requests that mean the same thing. If the intent is clear, count it as a success.

if you're understanding that the intent is an FCR that you count it as an FCR, because if you're saying like, Oh, well, you didn't say this... you're setting another demand instead of engaging in the intent of skills-based treatment From the talk. B. Kuerine Gray

Dr. Shane Spiker points to research that backs a broad request. He describes teaching an omnibus mand, which is a general ask like "my way." When you teach that broad request first, problem behavior drops more durably. It stays low even after you later teach more specific requests.

Teach tolerance, not just the request#

Asking is only step one. Real life sometimes says no. So good FCT also teaches the person to handle a denial. This keeps the skill strong when the answer is not yes.

Matt described this early sequence in his own case work. First they taught the request. Then they taught the child to accept when it was denied. Lauren Weaver used the same pattern in a school case. Her team taught a student to say "please give me some more time." Then they taught him to stay okay when the answer was no.

This step protects your progress. Without it, a single denial can trigger the old behavior again. With it, the person keeps their calm and their voice.

Write goals for where the learner is now#

A goal should match the person's current skill, not your dream skill. This is a common trap in school plans. Nikki warns against writing a full-sentence goal for a child who only says "no" today. That jump is too big and sets everyone up to fail.

She also stresses teamwork on these goals. A speech-language pathologist, or SLP, often shares this work. The goal may live under the communication section or the behavior section. Writing it together keeps the plan honest and doable.

You can also spread practice across people and settings. Kelly Brzak shared a sample goal where a child runs several FCT trials with two family members. Splitting practice this way builds success with more than one caregiver.

What the research says#

FCT has strong research support. A meta-analysis of 34 single-case studies looked at young children with autism. It found large effects for reducing challenging behavior and moderate-to-large effects for building replacement behavior. The authors still call for better reporting of maintenance and generalization (Blair, Park, & Risse, 2025).

FCT also holds up well in schools. A mega-review pulled together six reviews of FCT in education settings. It found steady positive effects on challenging behavior across studies. The authors note gaps in demographic reporting and review quality (Corr, Rispoli, & Welker, 2025).

Research also compares FCT to other options. One study chained differential reinforcement of compliance with FCT for escape-driven behavior. FCT produced larger drops in challenging behavior, and every participant preferred FCT (Ferris et al., 2026). Another study found that teaching more than one way to communicate may make treatment more durable (Livingston et al., 2025).

FAQ#

What is the difference between FCT and DRA? DRA means you reward a different behavior instead of the hard one. FCT is a focused type of that idea. It always teaches a communication response tied to the behavior's function. It also aims for skills that work with new people and in new places.

Do I have to use extinction with FCT? Traditional FCT pairs the request with extinction for the hard behavior. But it is not the only path. Matt Harrington shows you can reach similar effects by rewarding the request and targeting a smaller warning behavior. The key is a big gap in payoff between the request and the hard behavior.

How do I keep FCT working over time? Two things help most. First, teach the person to tolerate a "no" so a denial does not undo your work. Second, plan how you will thin the reward schedule so the request stays strong. Researchers keep testing the best ways to do this after FCT (Ramirez, León, & Bacotti, 2025).

Want to see this in real case work? Watch Solving Clinical Challenges with Research. One team turned a stuck FCT plan into a research search.