In applied behavior analysis, it is believed that all behavior occurs for a reason. Technically speaking, behavior analysts look at this idea with the behavioral principle that behavior is maintained by a function. In the ABA field, there are four functions of behavior.


The individual behaves in order to get out of or avoid doing something he/she does not want to do.

  1. EXAMPLE: Child throws ABA materials on the ground and is no longer required to complete the task that was presented to him or her. Child learns that throwing materials on the ground will get him or her out of having to do the work.
  2. EXAMPLE: Child puts his head down on the desk when presented with academic work. Child is not expected to finish the academic work. Child learns that putting his head down on the desk will get him out of doing the non-preferred task of academic work.

NOTE ABOUT ESCAPE: Escape-maintained behaviors may be due to lack of motivation to perform the task (they dont want to) or lack of skill (it is too difficult). Intervention should focus on increasing compliance as well as providing enough prompts for difficult tasks or taking a step back on tasks that are too difficult by providing tasks that are easier to accomplish and increasing the difficulty of the task more slowly.


The individual behaves to get focused attention from parents, teachers, siblings, peers, or other people that are around them.

  1. EXAMPLE: Child whines until parent attends to them. Child learns that whining will get attention from their parent.
  2. EXAMPLE: Therapist is talking with another adult (parent or another staff). Child throws item across treatment room. Therapist looks at child and explains to him that he needs to clean the toy up (or therapist starts interacting with child again). Child learns that throwing gets attention from therapist.

NOTE ABOUT ATTENTION: Attention doesnt have to simply be positive attention. The behavior may be maintained by attention that doesnt even appear to be that pleasant, such as the caregiver talking in a stern voice or trying to explain reasons why the child should engage in appropriate behavior.

Access to Tangibles:

The individual behaves in a certain way to get a preferred item or participate in an enjoyable activity.

  1. EXAMPLE: Child wants candy at the check-out line. Child says, I want some candy. Parent says no. Child cries and whines more about wanting candy. Parent lets child get candy. Child learns that crying and whining gets him or her the candy.
  2. EXAMPLE: Child wants to use a toy that he likes. Therapist is holding onto the toy. Child grabs toward the toy to take it (or child whines and grabs for the toy). Therapist gives the toy. Child learns that grabbing for the toy (with or without whining-instead of speaking or using PECS or other form of communication) gets him the toy.

NOTE ABOUT ACCESS: Access-maintained behavior may be simply the child gesturing toward something he wants, pulling a caregivers hand in the direction of what he wants, or just looking toward what he wants (when a caregiver has learned to read his body posture and facial expressions) or it can be more problematic behaviors like whining, throwing, etc.

Automatic Reinforcement:

The individual behaves in a specific way because it feels good to them. This is sometimes referred to as sensory behaviors.

  1. EXAMPLE: Child is crying because child has an earache. (In this example, the crying isnt due to a factor outside the childs body. Instead, it is due to an experience the child is having inside.)
  2. EXAMPLE: Child scratches his skin because of eczema or bug-bites to relieve itching.

NOTE ABOUT AUTOMATIC REINFORCEMENT: In the above example, scratching is not a self-injurious behavior as sometimes seen in escape or access-maintained behaviors. Although scratching ones self can be maintained by other functions, in this example, it is to relieve itching, an automatic or sensory experience.

Identifying the function of a behavior can help providers to identify the contingencies that are currently maintaining the behavior. By identifying the contingencies that are maintaining the behavior, the provider (or the parent) can then make changes to discriminative stimuli (SDs) and related consequences and/or to establishing operations and antecedents to ultimately impact the identified behavior (Hanley, Iwata, & McCord, 2003).


Hanley, G. P., Iwata, B. A. and McCord, B. E. (2003), FUNCTIONAL ANALYSIS OF PROBLEM BEHAVIOR: A REVIEW. Journal of Applied Behavior Analysis, 36: 147-185. doi:10.1901/jaba.2003.36-147