Functions of Behavior
The function of a behavior refers to the source of environmental reinforcement for it.
Functions of Behavior
"The function of a behavior refers to the source of environmental reinforcement for it." - Tarbox et al (2009, p. 494)
Four Common Functions of Behavior
Before getting more technical about the functions of behaviour we’re going to outline four common behavioural functions below.
#1 Social Attention
A person may engage in a certain behaviour to gain some form of social attention or a reaction from other people. For example, a child might engage in a behaviour to get other people to look at them, laugh at them, play with them, hug them or scold them.
While it might seem strange that a person would engage in a behaviour to deliberately have someone scold them it can occur because for some people it’s better to obtain “bad” attention than no attention at all (Cooper, Heron & Heward, 2007).
#2 Tangibles or Activities
Some behaviours occur so the person can obtain a tangible item or gain access to a desired activity. For example, someone might scream and shout until their parents buy them a new toy (tangible item) or bring them to the zoo (activity).
#3 Escape or Avoidance
Not all behaviours occur so the person can “obtain” something; many behaviours occur because the person wants to get away from something or avoid something altogether (Miltenberger, 2008).
For example, a child might engage in aggressive behaviour so his teachers stop running academic tasks with him or another child might engage in self-injury to avoid having to go outside to play with classmates.
#4 Sensory Stimulation
The function of some behaviours do not rely on anything external to the person and instead are internally pleasing in some way – they are “self-stimulating” (O’Neill, Horner, Albin, Sprague, Storey, & Newton, 1997). They function only to give the person some form of internal sensation that is pleasing or to remove an internal sensation that is displeasing (e.g. pain).
For example, a child might rock back and forth because it is enjoyable for them while another child might rub their knee to sooth the pain after accidentally banging it off the corner of a table. In both cases, these children do not engage in either behaviour to obtain any attention, any tangible items or to escape any demands placed on them.
Behaviours Occur for a Reason
A behaviour that a person engages in repeatedly will typically serve some kind of purpose or function for them (O’Neill, et al, 1997). Note the word “repeatedly” is used because people engage in all kinds of behaviours but unless a behaviour serves some kind of function for them it wouldn’t typically continue to occur.
When we say the “function” of a behaviour we basically mean “why” the behaviour is occurring. While it might be difficult to understand why a person does something (e.g. challenging behaviours such as self-injury or aggression) there will always be an underlying function (O’Neill, et al, 1997).
It’s worth noting that a behaviour can serve more than one function (Miltenberger, 2008). For example, a child might learn to hurt themselves during class to get out of having to complete academic tasks and then also hurt themselves in the playground to get attention from the teachers. Here the same behaviour – self-injury – serves two different functions depending on the environment the child is in.
Function (Why) vs. Topography (What)
If a child hurts themselves and we describe that behaviour as “self-injury” then we are describing the topography of the behaviour. Topography only describes “what” behaviour is occurring but it says nothing about “why” the behaviour occurs; this is where the function of the behaviour is needed because the function will describe “why” it is occurring (Cooper et al, 2007).
Another example would be if we said the person is “talking”. To say someone is talking is describing the topography of the behaviour but tells us nothing about the function. Someone might talk to another person to ask for directions, another person might talk to teach a class of students while another person might talk to chat up someone they want to date.
While a clear definition of the behaviour’s topography is needed, it is important to identify and describe the function of the behaviour through a Functional Behaviour Assessment (FBA). Without understanding the function of a behaviour any intervention put in place could be ineffective and/or make the behaviour worse (O’Neill et al, 1997).
Function and Reinforcement
The reason for a behaviour occurring can be described in terms of the function it serves or the reinforcement that is maintaining it (Miltenberger, 2008).
When we say the “reinforcement that is maintaining it”, this just means we can describe the reason the behaviour occurs in terms of the favourable outcome that the behaviour creates for the person (Miltenberger, 2008).
It doesn’t really matter whether you choose to describe the function of the behaviour or the reinforcement maintaining the behaviour because either way you are saying the same thing but just using different terminology.
That said, it can useful to use both terms when describing the function of a behaviour. For example, you could say: “the behaviour is being maintained by positive reinforcement; he is hitting his peers in the playground and the function of this behaviour is to obtain access to the swing set during lunch break”.
Two Broad Behavioural Functions
Broadly speaking, behaviours serve two functions; they either get a person something or get a person out of or away from something (Cooper et al, 2007).
When a behaviour gets a person something this is called positive reinforcement and when a behaviour gets a person away from something or results in an item being taken away from them this is called negative reinforcement.
To say a behaviour occurs because it either gets a person something or gets the person away from something isn’t really telling you all that much.
To get a clearer and more descriptive understanding of behavioural functions we need to be much more specific. To do this, we need to break down both positive and negative reinforcement into two more specific classes.
Social and Automatic Reinforcement
Positive reinforcement can be broken down into “social” and “automatic” positive reinforcement, while negative reinforcement can be similarly broken down into “social” and “automatic” negative reinforcement.
Social Positive Reinforcement
The first specific class of reinforcement is called “social positive reinforcement” and occurs when a behaviour gets a person something through the action of another person. Three examples of social positive reinforcement include:
Example One: A boy asking his mother for a glass of milk and then getting the milk from his mother. Here the boy’s behaviour of asking for milk required another person (his mother) to mediate his ability to obtain the glass of milk.
Examples Two: A comedian telling jokes and making people laugh. Here the comedian’s behaviour of telling jokes occurred in order to create a favourable outcome for him (people laughing) and this behaviour required other people.
Examples Three: A child asking their parents if they can go to the zoo at the weekend and then being told she can go. Similar to the boy asking for a glass of milk, here the girl wants access to an activity and the behaviour of requesting to go to the zoo requires another person/s for reinforcement to occur.
Automatic Positive Reinforcement
The second specific class of reinforcement is called “automatic positive reinforcement” and occurs when a behaviour gets a person something as a result of their own actions i.e. no-one else was involved in any way. Three examples of automatic positive reinforcement include:
Example One: A boy pouring his own glass of milk. Here his behaviour produced its own reinforcement by the fact that he got what he wanted and no-one else was in any way needed for reinforcement to occur.
Example Two: A child hand-flapping for personal enjoyment (self-stimulation). It’s important to note that just because a person engages in hand-flapping does not mean the behaviour is maintained by automatic reinforcement; this is why we specify that the hand-flapping occurs for personal enjoyment. Some people could engage in hand-flapping for various different reasons (e.g. to obtain attention).
Example Three: A child turning on a computer to play a game. Here the child’s behaviour of turning on the computer gets them access to the computer game and no-one else was needed.
Social Negative Reinforcement
The third specific class of reinforcement is called “social negative reinforcement” and this occurs when a behaviour gets a person away from something or gets something taken away from the person through the actions of another person. Three examples of social negative reinforcement include:
Example One: A boy asking his mother to take the vegetables off his dinner plate and his mother then taking them off the plate. Here the boy’s behaviour required another person (his mother) to mediate his ability to get rid of the vegetables.
Example Two: If you crossed the road to avoid talking to someone you don’t like. Here your behaviour is occurring to avoid an aversive situation that involves another person.
Example Three: A child at the playground screams at her Dad that she wants to leave and her father dutifully takes her away. Here the girl’s behaviour is occurring to avoid being at the playground but she needed another person (her father) to mediate the outcome.
Automatic Negative Reinforcement
The fourth specific class of reinforcement is called “automatic negative reinforcement” and this occurs when a behaviour gets a person away from something or gets something taken away from them through their own actions i.e. another person is in no way involved. Three examples of automatic negative reinforcement include:
Example One: When you brush your teeth to remove dirt. Here your own behaviour is reinforced by the fact that you get what you wanted – the removal of dirt from your teeth – and as you did the brushing yourself and no-one else was involved, it is termed “automatic”.
Example Two: Scratching an itch (Cooper et al, 2007). Here the function of the behaviour is to stop, reduce or avoid any kind of unpleasant internal stimulation or feeling. So before the behaviour occurs the person would be “feeling” some kind of unpleasant stimulation e.g. pain, and then after the behaviour this internal stimulation is gone.
Example Three: Avoiding having to complete a school report by tidying your room. Here the function of the behaviour is to get away from or avoid having to engage in some kind of activity as a result of your own actions i.e. no one else was involved with the avoidance of the activity. So before the behaviour occurs the person may be currently engaging in an unpleasant activity or be about to engage in the activity and then after the behaviour the person is able to get away from the activity or get out of having to engage in the activity
- Cooper, J., Heron, T., & Heward, W. (2007). Applied Behaviour Analysis. New Jersey: Pearson Education.
- Miltenberger, R. (2008). Behaviour Modification. Belmont, CA. Wadsworth Publishing.
- O'Neill, R., Horner, R., Albin, R., Sprague, J., Storey, K., & Newton, J. (1997). Functional Assessment and Programme Development for Problem Behaviour: A Practical Handbook. Pacific Grove, CA. Brooks/Cole Publishing Company.
- Tarbox, J., Wilke, A., Najdowski, A., Findel-Pyles, R., Balasanyan, S., Caveney, A., Chilingaryan, V., King, D. et al (2009). Comparing Indirect, Descriptive, and Experimental Functional Assessments of Challenging Behavior in Children with Autism. Journal of Developmental and Physical Disabilities, 21, 493-514. DOI: 10.1007/s10882-009-9154-8