Why Behaviour Happens

Behaviour is communication, and it is doing a job

Behaviour that keeps happening is behaviour that is working — it is getting something, or getting away from something. That is not manipulation and it is not naughtiness. It is how learning works, and it works exactly the same way in adults.

So the question is never "how do I stop this?" The question is "what is this achieving, and what could achieve the same thing more easily?"

The ABCs

A — Antecedent. What happened immediately before. The setting, the demand, the change, the noise, the person who walked in.
B — Behaviour. What actually happened, described so precisely that someone who was not there could picture it. Not "had a meltdown" — "screamed, threw the plate, ran to the bedroom".
C — Consequence. What happened immediately afterwards. Who came, what was said, what stopped, what was given.

Write these down for a week or two. Patterns that are invisible in the moment become obvious on paper, and the antecedent is usually where the answer is.

Also look at the setting events

Things that make a behaviour more likely without directly triggering it: poor sleep, illness, hunger, pain, a change at home, an earlier incident that day, a substitute teacher, constipation, a growth spurt, a new medication.

Setting events explain why the same request produces nothing on Tuesday and a crisis on Thursday. When someone says "it comes out of nowhere", this is usually where it came from.

The four functions

Almost all behaviour serves one of four purposes. Working out which one is the whole task.

1. To get attention or connection

Looks like: behaviour that happens most when you are busy, on the phone, or with a sibling; behaviour that stops when you engage.
Teach instead: a way to ask for attention that works — a word, a sign, a symbol, a tap on the arm. Then give attention generously and unpredictably at other times, so it does not have to be extracted.

2. To get something tangible

Looks like: behaviour when something is refused, ended, or when a turn is over.
Teach instead: requesting, waiting with support, and choice-making. Warn before transitions. Use a visual timer so the end of a turn is not a surprise.

3. To escape or avoid something

Looks like: behaviour at the start of a demand, at homework, at getting dressed, at a noisy environment. The behaviour ends when the demand does.
Teach instead: asking for a break, asking for help, and refusing acceptably. Then look hard at the demand — escape behaviour very often means the task is genuinely too hard, too long, too loud, or unclear. Sometimes the right answer is to change the task, not the person.

4. Sensory — it feels good, or it stops something feeling bad

Looks like: behaviour that happens whether or not anyone is around, and does not change much with the response.
Teach instead: a safe way to meet the same sensory need — heavy work, movement, chewing, deep pressure. And note carefully: if it is harmless, it may not need changing at all. Stimming is regulation, not a symptom to remove.

Why "it's just for attention" is a dead end

It is often accurate — and it tells you nothing about what to do, while implying the person is being calculating. Everyone seeks attention; it is a basic human need. The useful version is: this person needs connection and does not have an easier way to ask for it. That version comes with an obvious next step.

Replace, do not just remove

A behaviour that is meeting a real need cannot simply be taken away. If you remove it without teaching something else, either it comes back or something worse arrives in its place.

A good replacement is:

Easier than the behaviour. If asking for a break takes more effort than throwing the book, the book gets thrown.
Just as effective. It must work every time at first, immediately.
Possible for this person right now. A card to hand over, not a full sentence, if a full sentence is not available under stress.

Prevention beats response

Most of the useful work happens before anything goes wrong.

Adjust the antecedents you now know about: warnings before transitions, shorter tasks, choices, a quieter spot, doing hard things when the tank is fuller.
Teach the replacement skill when everyone is calm — never in the middle of an incident.
Meet sensory needs on a schedule rather than in response to trouble.
Notice and respond to the behaviour you want far more often than the behaviour you do not.

Some ground rules we work by

Safety first, always. If someone is at risk, the plan is safety — the analysis happens afterwards.
Never withhold food, drink, the toilet, sleep, comfort or communication in order to obtain compliance. Not as a consequence, not as leverage, not ever.
Assent matters. A person showing they do not want to continue is giving you information, and that includes a person who cannot say so in words.
Harmless is allowed. Not every unusual behaviour is a target. Ask who the behaviour is a problem for before deciding it is a problem.

You can read more about how we apply this in neurodiversity-affirming therapy.

When to get help

If a behaviour is unsafe for the person or anyone else, if it is happening across settings, if it is limiting participation at school, work or in the community, or if the adults involved have run out of road. A behaviour assessment identifies the function properly and builds a plan around it — and a plan built on the right function tends to work quickly, while a plan built on the wrong one never does.