Language as Verbal Behavior
B.F. Skinner defined verbal behavior as behavior whose reinforcement is mediated by another person who has been trained to provide that reinforcement. A speaker emits the behavior, and a listener mediates the consequence. Verbal behavior is not defined by its form (vocal, signed, written, or pictures) but by its function, meaning the variables that control it. The same word can serve as different operants depending on what controls it.
Skinner identified several elementary verbal operants. The six most commonly tested are the mand, tact, echoic, intraverbal, textual, and transcription (with related operants such as copying a text and taking dictation).
The Mand
A mand is a verbal operant controlled by a motivating operation and followed by a specific reinforcer. It is a request, demand, or command. Antecedent: an MO (for instance, thirst). Response: "Water, please." Consequence: receiving water, which is the specific reinforcer.
- The mand benefits the speaker directly.
- It is called "specific reinforcement" because the consequence matches the form of the response.
- A child who learned to say "cookie" only when shown a picture of a cookie has a tact, not a mand, unless the word is also under the control of the MO.
The Tact
A tact is a verbal operant evoked by a nonverbal stimulus (an object, event, or property of an object) and maintained by generalized conditioned reinforcement such as praise or confirmation. Antecedent: a dog is seen. Response: "Dog!" Consequence: "That's right!" The word "tact" derives from "making contact" with the environment.
- Tacts expand a learner's ability to comment and share.
- They are controlled by the stimulus, not by deprivation.
- Tacting can be extended, such as saying "dog" for a wolf (generic extension) or "sunny" for a person with a bright smile (metaphorical extension).
The Echoic
An echoic is a vocal verbal stimulus that evokes a vocal response with point-to-point correspondence and formal similarity, maintained by generalized conditioned reinforcement. Antecedent: the teacher says "ball." Response: the learner says "ball." Consequence: praise. Echoics are crucial for early vocal language, and echoic training often precedes teaching other operants.
Point-to-point correspondence means that the beginning, middle, and end of the stimulus match the beginning, middle, and end of the response. Formal similarity means the stimulus and response share the same sensory mode (both are auditory).
The Intraverbal
An intraverbal is a verbal operant evoked by a verbal stimulus that does not have point-to-point correspondence with the response, maintained by generalized conditioned reinforcement. Antecedent: "What do you wear on your feet?" Response: "Shoes." Consequence: praise. Intraverbals are the basis of conversation, answering questions, fill-in-the-blank tasks, and recounting events.
- A common error is labeling a response to a question about a picture as an intraverbal. If the answer is controlled by a nonverbal stimulus such as a picture, it is a tact (or a combination).
- Learners can have strong tacts without intraverbals, which is why intraverbal training must be taught directly.
Textual Behavior
A textual operant is a response evoked by a written verbal stimulus with point-to-point correspondence but without formal similarity. This is reading aloud. Antecedent: the written word "cat." Response: saying "cat." Consequence: generalized conditioned reinforcement. Note that textual behavior does not require comprehension; a learner may read words aloud without knowing their meaning.
Transcription (Taking Dictation)
In taking dictation, a spoken verbal stimulus evokes a written or typed response, with point-to-point correspondence but without formal similarity. Antecedent: the teacher says "cat." Response: the learner writes "cat." Related operants include copying a text, where a written stimulus evokes a written response with point-to-point correspondence and formal similarity.
Comparing the Operants
- Mand: MO-controlled; specific reinforcer.
- Tact: Nonverbal stimulus; generalized conditioned reinforcement.
- Echoic: Verbal stimulus with point-to-point correspondence and formal similarity; generalized conditioned reinforcement.
- Intraverbal: Verbal stimulus without point-to-point correspondence; generalized conditioned reinforcement.
- Textual: Written stimulus, vocal response, point-to-point correspondence, no formal similarity.
- Transcription: Spoken stimulus, written response, point-to-point correspondence, no formal similarity.
Functional Independence
Skinner argued that the operants are functionally independent: learning one does not guarantee the learner can do another. A child may tact an apple but not mand for one. Teaching programs should therefore include direct training across operants and also procedures to promote transfer, such as transfer of stimulus control. For example, an echoic prompt can be used to teach a mand, and then faded.
Teaching Applications
Mand training
- Identify items the learner wants using preference assessments.
- Contrive a motivating operation by withholding the item or providing a partial portion.
- Prompt the mand with an echoic, a model, or a sign prompt.
- Deliver the item immediately and specifically.
- Fade the prompt and expand to multiple forms, including "I want" frames and requests for information.
Tact training
Present objects and pictures and reinforce correct names with praise or tokens. Include generalization across examples, people, and settings.
Intraverbal training
Begin with fill-in-the-blank songs and routines ("The wheels on the bus go round and ...") and expand to social questions and categories. Use transfer of stimulus control procedures to fade prompts.
Assessments
The VB-MAPP and ABLLS-R are commonly used to assess verbal operants and related skills. The BCBA exam may ask which assessment evaluates verbal operants, and how to translate results into goals.
Exam Strategies
- Identify the controlling antecedent: an MO, a nonverbal stimulus, or a verbal stimulus.
- Determine whether the stimulus and response have point-to-point correspondence and formal similarity.
- Look at the consequence: specific reinforcement points to a mand; generalized conditioned reinforcement points to the others.
- Do not rely on topography. The word "water" can be a mand, tact, echoic, or intraverbal depending on the context.
Key Takeaways
Skinner's elementary operants classify verbal behavior by its controlling variables. Mands are controlled by MOs, tacts by nonverbal stimuli, echoics and intraverbals by verbal stimuli, and textual and transcription by written or spoken stimuli with different response modalities. Teach each directly and plan for transfer of stimulus control.