A definition of extinction
A very important concept in ABA is that of extinction.
Extinction occurs when, after a past history of reinforcement for a given behavior, that reinforcement is discontinued. In other words, extinction is the interruption of reinforcement for a behavior that had been reinforced in the past.
As a result of extinction, the future frequency of the behavior decreases.
Here is an example of extinction, which could happen to everyone, in everyday life:
Every time I press the button the light turns on (reinforcement administered). One day I press the button and the light doesn’t turn on anymore. I try and I try again, but nothing happens (extinction administered). The future frequency of my button-pressing behavior decreases. At least until the purchase of a new light bulb!
Extinction doesn’t always mean ignoring! Three types of extinction procedure
A common mistake is that of identifying extinction with ignoring the behavior. Although in some cases the extinction procedure consists precisely in that, extinction is not always the same as ignoring!
In order for the extinction procedure to be effective, it is necessary to identify the reinforcement, or the reinforcements, that maintain the behavior and to stop providing them as a result of such behavior.
In general, extinction procedures can be classified into three types (Cooper, Heron, Heward, 2007), extinction of behaviors maintained by:
- positive reinforcement,
- negative reinforcement and
- automatic reinforcement.
Behaviors maintained by positive reinforcement can be of two types:
- behaviors maintained by social attention and
- behaviors maintained by access to tangibles.
In the case of behaviors maintained by social attention, the extinction procedure actually consists in ignoring the behavior.
Let’s take an example:
When Pietro’s aunt visits him, she spends a lot of time playing with her nephew. However, whenever she sits on the sofa to have a chat with her brother and her sister-in-law, Pietro starts calling her and pulling her close to him and his aunt starts giving him attention and playing with him again (reinforcement administered).
One day the aunt realizes that Pietro’s behavior might be maintained by reinforcement in the form of attention and begins to ignore Pietro every time he calls her and pulls her close to him (extinction administered).
The future frequency of the behavior decreases.
In the case of behaviors maintained by access to tangibles, the extinction procedure consists in interrupting the delivery of the tangible reinforcement.
Let’s take an example:
Lucia yells at her brother Giacomo because she wants his Lego construction sets.
Giacomo locks himself in the bedroom. After a few minutes, while Lucia is still screaming, Giacomo hears the theme song of his favorite cartoon coming from the TV in the living room.
He comes out of the room and says to Lucia: “Okay you can have the construction sets, I’m not interested in them anymore!” (reinforcement administered).
The following days, Lucia screams again in order to have the construction sets, but Giacomo does not give them to her (extinction administered).
The future frequency of the screaming decreases.
If Giacomo had ignored Lucia, but had allowed her to take the Legos following the screaming, the behavior wouldn’t have diminished!
In the case of behaviors maintained by negative reinforcement, the extinction procedure consists in NOT removing the aversive stimulus, after the occurrence of the behavior. This procedure is called “escape extinction”.
Giulia and her ABA tutor work side by side. When the ABA tutor presents Giulia a new exercise with a difficult syllable for her, Giulia leaves the table and starts running around the room.
The ABA tutor takes her back to the table and introduces her to an easier exercise, which she already knows how to do (reinforcement administered).
Following the meeting with the supervisor, it is decided not to change exercise when Giulia returns to the table (extinction administered).
Over the days, the frequency of getting up and running around the room decreases.
If the ABA tutor had simply ignored Giulia, allowing her to get up and run, the behavior wouldn’t have decreased!
Finally, let’s talk about behaviors maintained by automatic reinforcement, that is to say those behaviors that are carried out because they produce a pleasant sensory stimulation for the person.
In this case the extinction procedure consists in masking or removing the consequent sensory stimulus. This is often done with devices such as rubber gloves, masking surfaces, safety glasses, protective helmets etc.
Let’s take an example:
When Marco is in his family’s car, he always bangs his hands on the roof for most of the route (reinforcement administered).
An analysis is carried out and it is concluded that the behavior is maintained by automatic reinforcement.
Marco’s mother covers the car roof with soft padding and Marco no longer gets the desired sensory stimulation (extinction administered).
The boy, in the following days, reduces his behavior of banging his hands on the roof until he no longer does it at all.
If Marco’s mother had ignored him the behavior would not have diminished!
In this case it is necessary to identify all the reinforcers and stop presenting them. An example:
Two educators are chatting aloud about one thing and another while Elena is eating. Elena begins to flicker her hands emitting high intensity vocalizations and the educators stop talking to each other, paying attention to the girl (reinforcement administered).
The behavior begins to occur whenever the educators talk to each other.
The behavior analyst intervenes and, after a careful analysis, establishes that the behavior is maintained by negative reinforcement (the educators stop talking every time Elena flickers her hands and emits vocalizations) and by positive reinforcement in the form of attention.
The educators, from that moment on, ignore Elena every time she emits the behavior and do not give her attention; moreover, they keep talking to each other (extinction administered).
The future frequency of the behavior decreases.
Perhaps, while reading so far, you may have thought:
“If only it were as easy as it is written in this article! If I ignore my son when he screams, he screams three times as much until he gets what he wants!”
Actually, what happens to your son is a perfectly natural and scientifically documented phenomenon.
This phenomenon has a name: “Extinction Burst“.
Extinction burst is an immediate and temporary increase in the frequency of the behavior, at the beginning of an extinction procedure. In addition, an increase in intensity and duration is also often observed.
In other words, before it gets any better, the behavior often gets worse. This is physiological and natural.
Let’s think about our own behavior:
If the TV doesn’t turn on, before we give up and we stop pressing the button on the remote, we will try over and over again. Only after a certain number of times we’ll “give up” and decide to desist.
Similarly, a girl who has always received her tablet following her screaming will scream even louder if her parents suddenly stop giving it to her, until she “gives up” and stops screaming.
It is essential to know the existence of the extinction burst since reinforcing a behavior during the burst is deleterious.
Repeated reinforcements during the burst in subsequent attempts to implement the extinction procedure can lead to the progressive worsening of behavior.
For example, let’s say that in the case of the girl and the tablet it takes 20 minutes for the screaming to stop and the girl to “give up“. If the parents “yield” and give the tablet to their daughter during the burst, the second time they decide to try again and put the behavior in extinction, it may take 50 minutes before she stops screaming, with louder screams, and so on.
If you start an extinction procedure you must be aware that the burst can occur and be ready to face it, preparing the setting and yourself adequately so that the procedure can takes place in complete safety.
Extinction can produce variability in responses
In addition to extinction burst, another phenomenon is also observed: extinction produces variability in responses (extinction induced variability, Morgan & Lee, 1996): that is, the person will begin to “try” different behaviors, in an attempt to gain access to the reinforcer.
Let’s think about the example of the TV that does not turn on:
In addition to trying several times to press the remote-control button, before giving up, we will also try other behaviors: for example, we can unplug and reattach the socket, try to change the batteries on the remote control, pull them out and try to put them back, turn them in various positions, shake the remote control. Only after several attempts, we will give up.
In the case of the girl, in addition to the screaming, other behaviors may appear: she may start kicking, throwing herself on the ground, crying, but she may also start asking for the tablet in an appropriate manner.
Actually, this phenomenon is not always disadvantageous: it can in fact lead to the appearance of more suitable responses and encourage the learning from the environment.
A study conducted by Lalli, Zanolli and Wohn in 1997 investigated the effects of extinction and positive reinforcement on the appearance of new appropriate interaction behaviors with various types of toys.
The participants were instructed to emit one functional play behavior with each toy. During the extinction phase, new appropriate play behaviors spontaneously arose.
Extinction can produce aggression
A side effect of extinction concerns the appearance of aggressive behaviors during it. This has been investigated in several studies such as that of Azrin, Hutchinson and Hake in 1966 or that of Kelly and Hake in 1970.
Extinction-induced aggression could be considered a form of variability in responses. As highlighted by Huffman in 2019, labeling these new emerging behaviors as “aggression” or “extinction-induced variability in responses” depends on our definition of “aggression.”
It is therefore not always possible to use an extinction procedure.
In the case of particularly serious and violent behaviors, precisely because extinction can induce the burst and even aggression, other behavioral strategies will have to be evaluated to solve the problem or it will be necessary to combine extinction with other procedures.
Something more about extinction…
In this article I gave a definition of extinction and explained some phenomena related to it.
For further information on the extinction burst and on strategies to implement it effectively, I invite you to listen to my podcasts which you can find on the “Data Driven ABA” Facebook page.