What are the 2 Main Functions of Behavior in ABA?

Have you ever wondered why some behaviors repeat themselves over and over? It’s not random—there’s always a purpose behind it. In ABA therapy, uncovering that purpose is the key to helping children grow and thrive.

When we understand what a child is trying to gain or avoid, we can support them with skills that make life easier, more predictable, and much more positive.

Why Understanding Behavior is the First Step in ABA

Before diving deeper into the two functions, it’s important to understand why behavior analysis starts here. In ABA therapy, we don’t focus only on what the behavior looks like. We focus on what the behavior achieves for the child.

This is called identifying the function of behavior.
Once ABA therapists know the function, they can:

• teach new communication skills
• reduce challenging behaviors
• support emotional regulation
• help the child succeed at home, school, and in the community
• improve daily routines and independence

Every effective ABA treatment plan starts with this foundation. It’s how ABA becomes individualized and meaningful—not a one-size-fits-all approach.

The two major categories of behavior are:

• Behaviors that happen to gain access or get something
• Behaviors that happen to escape, avoid, or get away from something

Each of these has several subtypes, which we’ll explore below.

Behavior Happens to Get Something

This first function is called access or positive reinforcement in ABA. It means the child uses behavior to obtain something that matters to them. Sometimes it’s obvious, and sometimes it’s much more subtle. But all “access” behaviors have one thing in common: they help the child achieve a desired outcome.

Getting attention

Attention is one of the strongest reinforcers for many children. It doesn’t matter if the attention is positive (“Great job!”) or negative (“Stop doing that!”)—both can reinforce behavior.

Some common attention-seeking behaviors include:

• calling out
• interrupting
• tapping or touching others
• acting silly to get a laugh
• crying or yelling to get a reaction

In ABA therapy, we often teach replacement behaviors such as raising a hand, saying a person’s name, or using a communication system.

Getting tangible items or activities

This includes any behavior used to access something the child wants right now. It could be:

• toys
• snacks
• screens or the iPad
• favorite activities (swinging, going outside, watching a show)

Children might grab, whine, cry, point, or pull an adult toward what they want.
ABA therapists use these moments to teach requesting skills—like asking with words, gestures, signs, or AAC devices.

Getting sensory input

Sometimes the behavior provides its own reward. This is known as automatic reinforcement. It’s common in autism because sensory needs vary widely and may impact how a child interacts with the world.

Examples include:

• hand-flapping
• rocking
• spinning
• humming
• tapping objects
• seeking deep pressure or movement

These behaviors meet a sensory need. ABA doesn’t eliminate sensory behaviors—instead, it aims to understand them and provide safe, appropriate ways to meet sensory needs.

Behavior Happens to Escape or Avoid Something

The second main function is escape or avoidance. This means the child uses behavior to get away from something uncomfortable, confusing, overwhelming, or unwanted.

Escape behaviors are extremely common in autism therapy, especially when communication or regulation skills are still developing.

Avoiding difficult or non-preferred tasks

Children may try to escape tasks that feel:

• too hard
• too long
• boring
• unfamiliar
• overwhelming

The behavior might look like:

• complaining
• refusing
• running away
• shutting down
• having a meltdown

In ABA therapy, we break tasks down into small steps and teach coping strategies and communication skills to reduce frustration.

Escaping overwhelming environments

Many children with sensory sensitivities try to avoid:

• loud noises
• crowded rooms
• bright lights
• chaotic or unpredictable places

A child might cover their ears, cry, push away, or leave the room.
ABA support includes sensory accommodations, preparing the child for transitions, and giving them tools to communicate discomfort.

Avoiding demands or expectations

Sometimes even a simple instruction—like “put on your shoes”—can trigger escape behavior. This may happen when a child:

• feels tired
• is having a hard day
• doesn’t understand the request
• lacks the skills needed for the task

ABA therapists teach skills such as asking for help, requesting a break, or negotiating (“Can I do this in one minute?”).

How ABA Therapists Identify Behavior Functions

Understanding the function of a behavior isn’t based on guessing. ABA uses tools such as:

• functional behavior assessments (FBA)
• direct observation
• data collection
• interviews with parents, teachers, and caregivers
• ABC analysis (Antecedent, Behavior, Consequence)

By studying what happens before and after the behavior, ABA therapists can confidently determine why it’s happening.

This allows us to develop a personalized, evidence-based behavior intervention plan that actually works in real life—not just in the therapy room.

Why These Behavior Functions are Helpful for Families

When parents learn about the two main behavior functions, everyday moments start to make more sense. Behavior becomes less confusing and easier to manage.

Here’s how this knowledge helps families:

• You understand what your child needs in the moment
• You can teach them better, safer ways to communicate
• You respond consistently instead of reacting emotionally
• You feel more confident during challenging situations
• You start to see progress at home and school

This is one of the reasons ABA therapy is so effective—it empowers not just the child, but the entire family.

Every behavior has a purpose. And in ABA therapy, understanding whether a behavior is happening to get something or avoid something is the first step toward meaningful change. At Milestone Achievements, we use this knowledge every day to support children with autism, help families build stronger routines, and create positive, lasting growth.

If you’re looking for compassionate, individualized ABA therapy in Georgia, we’re here to support your child’s journey. Contact us to learn more about our ABA services in Georgia!

We’re honored to help your child grow—one milestone at a time.

Sources:

• https://www.understood.org/en/articles/functional-behavioral-assessment-what-it-is-and-how-it-works
• https://psychcentral.com/autism/functionsofbehavioraba
• https://iris.peabody.vanderbilt.edu/module/fba-elem/cresource/q1/p01/