By Matt Harrington, BCBA · Behaviorist Book Club · Research-backed answers for behavior analysts
Skinner identified several elementary verbal operants based on the functional relationships between the verbal response and its controlling variables. The primary operants are: mands (controlled by motivating operations and reinforced by characteristic consequences), tacts (controlled by nonverbal stimuli and reinforced by generalized conditioned reinforcement), echoics (controlled by a verbal stimulus with point-to-point correspondence and formal similarity), intraverbals (controlled by verbal antecedents without point-to-point correspondence), and textual operants (controlled by written stimuli). Each operant has a distinct antecedent-consequence structure that requires its own training approach.
Traditional linguistic approaches focus on structural features of language — syntax, grammar, phonology — and treat language as a knowledge system that speakers use to produce utterances. Skinner's framework treats verbal behavior as a category of operant behavior maintained by environmental contingencies mediated through other people. The analysis focuses on the function of verbal responses — why this response occurs in this context with this person — rather than on its structural properties. This functional emphasis is what makes Skinner's framework clinically actionable: it identifies what variables need to be manipulated to produce targeted verbal responses, not just what form those responses should take.
A learner may demonstrate different levels of acquisition across verbal operant types even when the surface form of the verbal response looks identical across contexts. A child who can name an apple when shown one (tact) may not be able to request an apple when hungry (mand) or answer "what do you eat for a snack?" (intraverbal), even though all three responses share the same topography. Treating these as a single linguistic ability leads to training procedures that fail to address the functional deficits limiting the learner's generative communication. Differential operant assessment identifies these distinct deficits and directs intervention to the specific antecedent-consequence structures that need development.
Multiple control occurs when a verbal response is simultaneously under the influence of more than one type of controlling variable. A tact response may also have intraverbal and mand components influencing its probability of occurrence in natural contexts. Clinical significance: when a response is trained under only one type of control — for example, exclusively as a tact — it may not occur spontaneously in motivational contexts that would evoke a mand, or in conversational contexts that would evoke an intraverbal. BCBAs must design training programs that systematically bring target responses under multiple forms of control to support the flexible use of language that characterizes functional communication.
Motivating operations (MOs) are the primary antecedent control variable for mand behavior. An establishing operation increases the reinforcing value of the mand's characteristic reinforcer and increases the probability of the mand response; an abolishing operation has the opposite effect. Effective mand training requires that instructional sessions occur when relevant MOs are in effect — when the learner genuinely wants the reinforcer the mand is designed to access. Training mands in the absence of relevant MOs produces prompted responses that lack genuine mand function and typically fail to maintain or generalize to natural contexts where the MO is the primary antecedent variable.
VB-MAPP results should be interpreted by first examining the profile across skill areas rather than focusing only on overall score or milestone level. A learner who scores strongly on tacts and echoics but shows deficits in mands, listener behavior, and intraverbals has a specific functional profile that suggests different intervention priorities than a learner with uniformly distributed deficits. Barriers assessment data should be reviewed alongside milestone scores — significant barriers such as prompt dependency, echolalia, or motivational deficits directly affect how treatment is structured. VB-MAPP scores should be re-assessed periodically to track progress and adjust treatment priorities as the learner's profile changes.
Mand training that relies on deprivation-based motivating operations must balance instructional effectiveness against the learner's welfare and dignity. Establishing mild states of motivation — conducting mand training before meals, incorporating preferred items into naturalistic teaching contexts — is generally appropriate. Establishing extreme or prolonged deprivation to increase instructional control creates unnecessary distress and violates the spirit of BACB Ethics Code (2022) Standard 2.14, which requires the use of the least restrictive procedures consistent with effective treatment. All mand training programs should ensure that the learner has multiple pathways to reinforcement beyond the targeted verbal response.
Functional communication training (FCT) is a verbal behavior application that directly addresses challenging behavior maintained by specific reinforcement contingencies. When challenging behavior functions as a mand — accessing attention, escaping demands, or obtaining tangibles — FCT teaches a communicative mand response that contacts the same reinforcement. The verbal behavior analysis is critical to FCT design: the replacement behavior must function as an effective mand in the same motivational context as the challenging behavior, must be reinforced with the same or similar characteristic consequence, and must be more efficient than the challenging behavior in accessing that reinforcement. Without this functional analysis, FCT may teach a topographically appropriate response that fails to compete with the challenging behavior.
Intraverbal training is challenging because intraverbal responses are controlled by verbal antecedents without point-to-point correspondence — there is no physical referent to anchor the response, and the antecedent-response relationship is arbitrary. This makes generalization particularly difficult: a learner who can answer "what do you drink?" may not be able to answer "what do you pour into a glass?" even though both questions target the same response. BCBAs should approach intraverbal training by first establishing the target response under tact and echoic control, then systematically transferring stimulus control to verbal antecedents using a transfer trial procedure, with sufficient variation in verbal antecedents to establish genuine intraverbal control.
Generalization must be programmed systematically rather than hoped for as a byproduct of acquisition training. For verbal behavior targets, generalization programming should include training with multiple stimulus exemplars across materials, people, and settings; testing with novel untrained stimuli and interlocutors before declaring mastery; incorporating natural environment teaching that exposes learners to the variability of real communicative contexts; and conducting generalization probes as a standard component of the mastery criterion rather than as an afterthought. When generalization probes reveal limited transfer, the instructional approach should be modified before moving to new targets — not treated as evidence that the learner is incapable of generalized responding.
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All behavior-analytic intervention is individualized. The information on this page is for educational purposes and does not constitute clinical advice. Treatment decisions should be informed by the best available published research, individualized assessment, and obtained with the informed consent of the client or their legal guardian. Behavior analysts are responsible for practicing within the boundaries of their competence and adhering to the BACB Ethics Code for Behavior Analysts.