What Is the Function of a Behavior and Why Does It Matter in Schools?
If you’ve ever changed an entire lesson plan just to avoid making copies because you know the copier is having a day, then you already understand the function of behavior better than you think.
Every behavior, yes, EVERY BEHAVIOR, a toddler’s tantrum or a high schooler’s side-eye, serves a purpose. And when we figure out what that purpose is, we can stop reacting and start responding in ways that actually support students. Let’s talk about what “function of behavior” really means, why it matters in your classroom, and how knowing the why behind a student’s actions can shift everything from power struggles to progress. Understanding the function of a behavior isn’t just for when you’re writing an FBA or addressing behavior goals in an IEP. This way of thinking can help us in every interaction we have.
What Do I Mean by “Function of Behavior”?
In technical terms, the function of a behavior is the reason the behavior continues. It’s the “why” behind what we see in the classroom.
Think of a student’s behavior like a vending machine. The student “presses a button” (engages in a behavior) and gets something out of it (a result that works for them). That result might be attention, avoiding something, getting something they want, or fulfilling a sensory need.
This is super easy to see in babies and toddlers. They’re constantly experimenting with what will get them attention or tangible items. And when it works? You better believe they’ll try it again.
The Four Primary Functions of Behavior
Sometimes, student behavior can seem totally random. One minute they’re fine, the next they’re under the table. But here’s the thing: there’s almost always a reason behind it. And no, it’s not just to make your day harder (even if it feels like that sometimes).
Even if it’s not obvious right away, that behavior is working for them to serve a purpose. Once we understand what a student is trying to get, avoid, or deal with, we can respond in a way that actually helps. Most behaviors fall into one or sometimes more of the four main categories.
1. Access or Avoid Attention
While “attention” is probably the most discussed function of behavior, I really like to think of this as “connection.” But when students can’t get a connection, any attention is the next best thing, even if it’s negative attention for disruptive behavior.
On the flip side, you can probably relate to pretending not to see someone in the store when you’re not in the mood to talk to them. Avoiding attention is a very common function as well.
Everyday example: You pretend to be busy so you can avoid a conversation you don’t want to have. Or, you FaceTime your bestie when you’re feeling bored.
In school: A student might call out, crack jokes, or even pick fights. It may look like they’re trying to cause trouble, but they’re often trying to connect with adults or peers. Or, they may avoid eye contact with you when you’re about to call on someone for an answer.
2. Access or Avoid Activities or Tasks (Work!)
This most often shows up when a student is trying to get away from something hard, boring, frustrating, or even emotionally overwhelming. You don’t have to look hard to find a student trying to avoid doing classwork. But, we also see students who rush through their work so they can gain access to the fun activities that are coming up next!
Everyday example: You skip the gym and take a long walk with an iced coffee.
In school: A student may push a worksheet away, walk out of the classroom, or put their head down when they perceive it’s too hard. If the behavior results in avoiding a task or person, escape is likely the function.
Tip: Pay attention to what happens right before the behavior. That’s often what they’re trying to avoid.
3. Access or Avoid Tangibles
This is the “I want something” or “get that away from me” function.
It’s pretty easy to see this one, because we’ve all wanted or not wanted things before. Especially when it comes to food, what food do you hate? For my husband, he would rather skip lunch than eat a burger with Swiss cheese.
Everyday example: You shake the vending machine because your snack got stuck. Or, you recycle a stack of old papers because you’re tired of looking at them.
In school: A student may scream for a toy, grab a classmate’s pencil, or demand their tablet. They may also knock their peas on the ground or throw a toy that they’re tired of.
Tip: Ask yourself: Does the behavior stop when the student gets the thing? If yes, then access to that item is probably reinforcing the behavior.
4. Access or Avoid a Sensory Experience (AKA “Automatic Reinforcement”)
Some behaviors just feel good or help a student self-regulate. We can all relate to this. Think about the last time you turned off the overhead fluorescent lighting in your classroom, cut the itchy tag off a shirt, or stood in front of a fan on a hot day. These are all behaviors that you engaged in simply because they felt good.
For most of us, sensory experiences like noise, textures, and lights can be irritating. Personally, I would never buy a toy for my toddler that plays the same song on repeat.
But for some people, especially those with disabilities that cause sensory integration issues (think autism or ADHD), even a little of the wrong sensory input can be overwhelming. And, the right sensory experience (flapping, swinging, humming, deep pressure squeezes) can be imperative to help regulate. These behaviors are incredibly reinforcing because they instantly feel good.
Everyday example: To access the right level of sensory input, you listen to music while driving on the highway, but then turn it down when you think you missed your exit.
In school: A student might rock, flap, hum, or pick at things. These behaviors often aren’t about gaining anything; they meet a personal sensory need.
Tip: If the behavior happens even when no one is around to witness it, there’s a good chance it’s sensory-related.
Why Does “Function of Behavior” Matter?
If we don’t understand why a student is doing something, our response might actually make things worse. For example, if we think a student is throwing their worksheet to get attention, so we ignore them, but the actual function is to escape from the work, we just made it more likely that they’ll throw the next worksheet too.
If we guess the wrong function, we could accidentally reinforce the behavior we’re trying to reduce. That means the behavior might happen more often, not less.
But if we understand the true function, we can teach the student a better, more appropriate way to meet that same need.
When we focus on function, we shift from punishment to problem-solving, and along the way, we build empathy too. After all, we’ve all sought connection and avoided things that are hard before.
Function of Behavior Resource
Ready to turn behavior observations into real insight? Grab the ABC Data Collection Bundle—your all-in-one toolkit for tracking behavior with purpose.
With editable forms, checklists for identifying function, and built-in graphing templates, this bundle makes it easy to collect, organize, and use your data. Whether you’re prepping for an IEP meeting or just trying to make sense of daily patterns, this resource saves you time and helps you take confident next steps.
Get the ABC Data Collection Bundle today and make your next behavior plan your best one yet.
What’s Next?
Now that you understand the function of behavior and why it matters, you’re ready to dig deeper.
Up next in this series: How to Collect ABC Data That Actually Helps.
By learning to decode behavior, we stop chasing quick fixes and build long-term strategies that truly support our students. You’ve got this, and I’m here to help every step of the way.
