Functions of behaviour

Why do people behave the way they do???

This is what first attracted me to study psychology but I never heard of Applied Behaviour Analysis (ABA) during those 4 years of study. When I did stumble across ABA  – the science of human behaviour – I instantly fell in love with it.

Here was a science that could not only explain why we behave the way we do, but also provide us with the necessary tools to actually change behaviour. I think this is amazing.

When I first learned about the functions of behaviour I had an ‘ah-ha’ moment and since then feel a bit like Neo in The Matrix – I find myself analysing behaviour ALL THE TIME because if fascinates me watching the principles at work.

THIS was the missing piece of the puzzle that I had been searching for.

As behaviour analysts (and parents!) we need to collect information to help us understand WHY a person’s behaviour has become effective for them.  We see behaviour as functional for a person, not simply because of a disability. The responses that a certain behaviour receives influence the likelihood of that behaviour occurring again in future but that’s content for my next blog!

When we’re trying to understand why a particular behaviour keeps happening we need to focus on the FUNCTION of behaviour (the purpose the behaviour serves), rather than what the behaviour looks like (called the topography).

Function; the purpose that the behaviour serves an individual:

  • To get something
  • To avoid, delay or escape something

Topograhy: What the behaviour itself looks like, what we observe, a precise and specific description of the behaviour.

Ok, that’s a lot of terminology – what does this actually look like in real life?!

Let’s say you have a child who is disruptive while doing class work – making paper airplanes, talking loudly to classmates, making goofy noises – and the teacher sends the child to the head teacher because he is so disruptive. This child may be disruptive because he is trying to ESCAPE from doing the class work. While the teacher’s consequence is logical, it is also ineffective. In this case, the child succeeded with escaping from class work and so the disruptive behaviour is likely to occur again.

Take the same exact behaviours and teacher response, but this time the function of the child’s behaviour is to get ATTENTION from classmates. In this case, the teacher’s consequence of removing him from the classroom should help to decrease the disruptive behaviour because she is targeting the correct FUNCTION of the behaviour – seeking attention.

This is why it is so important not to only focus on the topography of the behaviour when determining intervention strategies. It is more useful to target the function of the behaviour.

The science of behaviour tells us that there are 4 main functions of behaviour;

> attention-seeking

> access to tangibles

> escape/avoidance

> automatically rewarding (another person does NOT need to be present unlike the top 3)

Let’s take a closer look at each of these functions…


Have you ever heard of the phase; “any attention is good attention”?? Attention consists of any verbal acknowledgment (i.e. social praise or a reprimand), physical contact (e.g. cuddle, hand holding), eye contact (yes – even an eye roll as your turn away!), facial expressions.

Access to tangible:

In other words – getting the good stuff e.g. toys, food, activities


Something in the environment that the child DOESN’T LIKE e.g. discontinuing a demand or task, leaving a setting/person

  • “I do not want to do what you told me to do”
  • “I don’t want to do it right now”


Simply put – It feel/tastes/sounds nice.  The behaviour itself feels good i.e. sensory input, hand flapping, echolalia, twirling, chewing.

E.g. Jack is on his own flapping his hands. Mum comes into the room to try and soothe him but he continues hand flapping.

This function also includes pain attenuation.

E.g. Ellie is sitting on her own in the garden scratching her legs. When her dad goes to her he discovers that she has lots of insect bites on her legs.

Let’s take a look at some examples to solidify all of this information:

Example of a ‘positive’ behaviour;

A – child feels hungry and sees fruit bowl

B – “can I have an Apple?”

C – mum says “sure, nice asking”

What might the function be??…

….access to tangible

Example of a ‘negative’ behaviour;

A – mum says it’s time to turn off TV

B – child starts whining and repeatedly asking for longer

C – mum caves and allows 5 more minutes

What might the function be?…

……access to tangible

Take home point:

People engage in any behaviour (whether we deem it appropriate or inappropriate) either:

  • to get good stuff, or
  • escape aversive stuff.

To watch a video I did with Dr Amanda Kelly (aka Behavior Babe) on functions click here (and excuse my dog barking!):

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