Picture two toddlers in your room right now.
One is throwing puzzle pieces across the carpet. Every time she does, her key worker calls out her name, walks over, and crouches down to help. She looks up, grins, and hurls another piece.
The other one is also throwing puzzle pieces. He’s been sitting at that puzzle for twelve minutes. It’s too hard and he knows it. Every piece he throws ends the session. The puzzle disappears. The demand goes away.
Same behaviour. Same room. Completely opposite reasons.
If you respond the same way to both of them, you will accidentally make at least one of those behaviours stronger.
Behaviour That Works, Repeats
Under-5s are not acting out because they’re bad kids or because their parents aren’t strict enough. They’re acting out because the behaviour works.
At two and three, most children don’t have the words yet for what they need. They can’t tell you they’re overwhelmed, that the transition feels unfair, that they desperately want you to come and sit with them. So they do the next best thing: they do whatever has worked before.
The technical term is function — what the behaviour is getting the child. Not what it looks like, not how loud it is, but what outcome it reliably produces. That’s the piece most responses miss entirely.
Once you know the function, the behaviour stops being random. It becomes predictable. And predictable behaviour is manageable behaviour.
The Four Reasons Under-5s Act Out
In behaviour analysis, almost every challenging behaviour a young child shows maps onto one of four functions. Here’s how each one looks in a childcare or preschool setting:
1. Attention
The behaviour gets a reaction from an adult or another child. It doesn’t have to be positive attention — it just has to be attention.
A three-year-old in group time who keeps poking the child beside her and laughing when the educator turns to say her name. The poking isn’t random. It works. Every poke = a look, a word, a moment of connection.
2. Escape
The behaviour gets the child away from something uncomfortable. A demand, a transition, a noise, a texture, a person who’s standing too close.
A two-year-old who melts down every time the room switches from free play to mat time. Not because mat time is inherently terrible — but because the meltdown has reliably ended the transition or delayed it long enough that he got a few more minutes on the floor.
3. Access
The behaviour gets the child something — a toy, an activity, a food item, a specific spot on the mat.
A four-year-old who hits to get the scooter. She’s not dysregulated. She’s efficient. She’s learned that hitting is faster than waiting.
4. Sensory
The behaviour feels good on its own, regardless of what anyone else does. This one’s important to understand because it can persist even when a child is completely alone — there’s no adult reaction driving it.
A two-year-old who bangs his head rhythmically against the wall during quiet time. He’s not upset and he’s not seeking attention. The input itself is what he’s after.
When you’re not sure which function fits, start with what happens right before and right after the behaviour. The pattern usually becomes visible within a few observations. This is also exactly what the function of behaviour framework is built around.
Why the Function Changes What You Do
Here’s where it gets practical — and where a lot of well-meaning responses go sideways.
Take picking up a crying toddler and offering a cuddle. That response:
- Works beautifully for attention-maintained behaviour, because you’re giving the child precisely what they were after. If you pair it with a replacement skill — a tap on your arm, a reach — you can teach the child a better way to ask.
- Makes escape-maintained behaviour stronger, because you’ve just removed the demand by picking the child up. The crying worked. Next time the demand appears, the child will cry sooner and louder.
Same response. One function it settles, the other it accidentally feeds.
This is the same logic that applies when you’re choosing rewards and de-escalation strategies at any age. A preferred item handed over during distress doesn’t always reinforce calmness — it depends entirely on what function the distress is serving. There’s a longer version of this argument in The iPad is Not a Reinforcer, which is worth reading alongside this one.
Knowing the function isn’t just useful for reducing the behaviour. It tells you what the child actually needs — which is the more important question.
Behaviour as Communication → Teaching the Words
The goal was never just to stop the throwing or the hitting or the meltdowns. The goal is to give the child a faster way to get the same thing.
If a child hits to get the scooter, and hitting works, they will keep hitting. If you block the hit and immediately prompt them to point, sign, or say “my turn” — and then give them the scooter — you’ve just made communication more efficient than aggression. That’s the whole trade.
This approach has a name: functional communication training, or FCT. The word, sign, or picture card replaces the problem behaviour because it gets the child to the same outcome. You can read more about it in the functional communication training (FCT) glossary entry.
It takes repetition. It takes prompting. It takes every adult in the room doing the same thing. But it’s not complicated in principle: you’re just teaching the child that their behaviour has words.
How to Spot the Function Without a Clipboard Crisis
You don’t need a formal behaviour assessment to start making educated guesses about function. Most early childhood educators are already doing informal observation — you just need a small frame to make it deliberate.
Watch what happens right before the behaviour. Was there a demand? A transition? Did another child take something? Did you turn your back?
Watch what happens right after. Did an adult come over? Did the demand go away? Did the child get something? Did the behaviour continue on its own without any apparent social consequence?
That before-and-after sequence — antecedent, behaviour, consequence — is the ABC pattern. Run it a few times for the same child and you’ll start seeing the same context repeat. That context is your clue.
If you want a simple paper tool for tracking this in a busy room without disrupting your day, the ABC data collection sheet is a one-page format designed for exactly this. You’re not doing a functional analysis — you’re just starting to see the pattern.
Start With the Function
Before you build a support plan, before you call a family meeting, before you wonder whether this child needs a referral — look at the function.
Ask what the behaviour is getting the child. Ask whether your current response is teaching them something more efficient, or just making the problem behaviour work a little harder.
Everything else follows from there.
We’ve gathered the full early-years toolkit at Understanding Behaviour in the Early Years.