As we learned in previous modules, behaviour is everything a person does. Outside of behaviour analysis, people may contrast behaviour with thoughts, feelings and actions. But when behaviour analysts talk about these subjects, they are all considered behaviour and/or stimuli.
Verbal behaviour is behaviour that is reinforced through the mediation of another person?s behaviour. That is to say, verbal behaviour is any behaviour where the production of the reinforcer is socially mediated.
Sometimes, people think that verbal behaviour must be vocal or language based. This is not the case.
For example, if you want a door to be open, point at a door and somebody else opens it, then you have engaged in verbal behaviour. This is because the reinforcer was produced by the behaviour of somebody else.
Verbal behaviour is defined by its function rather than its form and can occur across multiple modalities. The analysis of verbal behavior involves the same behavioral principles and concepts that make up the analysis of nonverbal behavior. However, while no new principles are required, there is some new terminology.
Classifying Communication using behaviour analysis
Traditional forms of communication analysis focus on its structure and topography (i.e. what it looks like). It may be analysed in terms of grammar, phonemes , semantics and lexicon. Which such forms of analysis may be useful in some circumstances, behavior analysts typically focus on the function of behaviour.
You?ll remember that we talked about the three and four term contingencies in earlier modules. We also looked at pragmatic categories of behavioural function and ways in which we can classify reinforcers. When using a verbal behavior approach, we talk about communication in terms of what happened before the behavior and what came after. Let?s look at some examples:
Listener Behaviour and Discrimination Training
Discrimination Training refers to procedures that result in certain behavior having different occurring more or less often in different situations. That is to say, it is the process that leads from unconditioned stimuli becoming an SD.
For example, if somebody asks you for an apple and you hand them an apple, your behavior will be reinforced. But if you handed them a screwdriver when they asked for an apple, your behavior would not be reinforced.
Through discrimination training, we become members of a verbal community. A verbal community is a group of people who learn to react to speaker behaviors in line with certain customs. It is roughly analogous to a group of people who speak the same language.
The main roles of the listener in verbal behavior is to:
1. Act as an SD and MO for speaker behavior
2. To mediate the delivery of reinforcement to the speaker in line with the customs of the verbal community
Next we?ll look at some categories of speaker behaviour.
Mands
Mands are typically requests, demands, or commands.
A mand behavior specifies its own reinforcer. It occurs in response to some motivating operation. Its consequence is reinforcement related to that motivating operation.
Imagine you have went for a long walk. You have not had water in a long time. This means that you are thirsty. In behavior analytic terms we would say that due to deprivation, there is an establishing operation (EO) in place for water. That EO increases the value of water as a reinforcer, and makes it more likely you?ll engage in behaviors that have produced water in the past.
You ask your friend for some water, and they hand you a glass of water.
This is an example of a mand because:
- There is a motivating operation in place for the speaker
- The speaker engages in a behaviour that specifies a reinforcer
- A reinforcer is delivered by a listener
Remember, a mand is a form of verbal behavior, because the delivery of reinforcement is socially mediated. It influenced the behavior of somebody else. Putting money into a vending machine to get water would not have been verbal behaviour. Likewise, while in our example, you vocally asked for the water, it would still be verbal behavior if you had used sign language or picture exchange to ask for the water.
Other examples of mands would likely include signing ?Give me the phone?, tapping an icon on a communication device to say ?Don?t do that? or vocalising the phrase ?Where is the i-Pad?.
Tacts
The category of tacts refer to when a speaker labels things in their environment. While mands occur in response to a motivating operation, tacts are under stimulus control. That is they occur in response to an SD. More specifically, a non-verbal SD. They typically result in generalised conditioned reinforcement. Usually in the form of social interaction.
A good example of a tact, is when a child points to a dog in the park and says, ?Look Mommy, it?s a dog!?. The likely response of the mother, in this scenario, is that she will say? something like, ?Yes Honey, that?s right. It is? a dog?.
This is an example of a tact because:
? There is a non-verbal SD. That is, The presence of the dog.
? The speaker?s response, is under the control of that non-verbal SD.
? A reinforcer (social reinforcement) is delivered by a listener
We know it is not a mand, because the child does not want the dog. The child?s verbal response, did not specify its own reinforcer.? This behaviour was under stimulus control, rather than motivation control.
Next we?ll look at intraverbal behaviour.
Intraverbal
Intraverbals are a category of verbal behavior, where somebody responds to another person?s verbal behaviour.
For example, somebody asks a teenager ?Where do you go to school? and the teenager responds ?Jigsaw?.
The difference between a tact and an intraverbal is that while tacts occur in response to a non-verbal SD, an intraverbal response occurs in response to a verbal SD ? typically produced by a conversation partner.
Like a tact, reinforcement for intraverbal behavior is typically generalised conditioned reinforcement in the form of social interaction. Without intraverbal responding, we cannot engage in conversations.
Echoics
Echoics are similar to intraverbals. Like intraverbals, they occur in response to a verbal SD. However unlike intraverbals, the response always has ?point to point correspondence? with the verbal SD. That is, they are identical to the SD (or near identical).
An intraverbal response to the verbal SD ?How old are you?? might be twenty. An echoic response to the same verbal SD would be ?How old are you??
In essence, an echoic response is one that imitates the verbal SD. Reinforcement is typically generalised conditioned reinforcement in the form of social reinforcement (e.g. praise).
Membership of multiple categories
It is worth noting that not all communicative responses fall neatly into a single category of verbal behavior.
For example, a child may go into a shop a point to a toy. They might say ?Look Mom, it?s Pikachu!?. In this instance, the behavior may be part-mand and part tact. It occurred both because of a motivating operation (e.g. wanting the toy) and because of a the presence of a non-verbal SD (the introduction of the toy into the environment).
Similarly, somebody might mand to somebody for information by saying ?How do you feel??. Their response of ?I?m feeling hungry? might be part-intraverbal and part mand. This is because the behaviour (saying ?I?m feeling hungry? occurred in response to verbal SD (?How do you feel??) but it also occurs in response to a motivating operation and is often results in people offering food.
Reinforcement Contingencies
In describing mands, tacts, echoics and intraverbals, we described their characteristic reinforcers. Remember, that many behaviors are maintained on intermittent schedules of reinforcement. This means that not every response is reinforced. A mand may not always result in the specified reinforcer and a tact may not always result in generalised social reinforcement.
Why are these categories useful?
When teaching somebody to communicate, we need to take consideration of the circumstances under which we want them to use a particular response ? i.e. what is the function of the response. This is particularly important when working with people with intellectual and developmental disabilities.
Focusing solely on topography can lead to suboptimal results. Let?s look at an example.
Tia is teaching Mark how to sign for a drink because he sometimes engages in behaviours that challenge when thirsty. She tells him to ?Ask for a drink?, she then prompts him to ask for a drink by sign and gives him a bottle of water. Mark does not drink the water.
What did Tia do wrong?
Well, Tia?s goal is to teach Mark to ask for drink when he is thirsty. The goal is for the target behaviours (making the sign for drink) to occur under the control of his motivation. However, she is only teaching him to make the sign in response to her verbal SD (i.e. Ask for a drink).
She is trying to teach a mand, but her teaching procedure only teaches Mark to make the sign ?Drink? as an intraverbal response. The reinforcer is not a drink, but the removal of Tia?s demand.
While many learners may first learn something as a tact or an echoic response, then generalise that response across the other verbal behavior categories, this is not always the case for people who have communication difficulties.
A person with communication difficulties may be able to use a word or sign as a tact, but not as a mand. Similarly, they may be able to echo a word, but not use it appropriately as an intraverbal response.
In ABA, knowledge of the functional categories of verbal behavior allows us to design teaching protocols in a way that maximises the chances of someone learning to use their verbal behavior in a contextually appropriate manner.