In the science of human behavior, actions are frequently sustained not by the social reactions of others, but by the immediate physical sensations produced by the behavior itself. An automatic reinforcer is an operant consequence that is generated directly by the response independently of the social mediation of another individual. Understanding this fundamental behavioral phenomenon illuminates why behaviors ranging from benign sensory habits to severe self-injurious actions persist across natural and clinical environments.
Automatic Reinforcer
1. Concise Definition
An automatic reinforcer is any stimulus change produced directly and naturally by a behavioral response that subsequently increases or maintains the future frequency, duration, or intensity of that response in similar environmental conditions, occurring entirely without the mediation of another person. In the framework of operant conditioning, while socially mediated reinforcers rely on a communicative partner or caregiver to deliver an appetitive stimulus or remove an aversive one, an automatic reinforcer is an inherent, unmediated physical, sensory, or physiological byproduct of the action itself.
This operant mechanism encompasses both appetitive sensory feedback (automatic positive reinforcement) and the direct attenuation or termination of physiological discomfort or aversive bodily stimulation (automatic negative reinforcement). Because the contingency is biologically or physically coupled to the response topology, behaviors maintained by automatic reinforcers pose distinct challenges and theoretical questions within functional behavior assessment and clinical behavioral intervention.
2. Etymology & Linguistic Origin
The term is composed of two classical linguistic roots that merged within twentieth-century behavior analysis. The word automatic derives from the Ancient Greek automatos (αὐτόματος), meaning “acting of one’s own will, self-moving, or self-acting,” composed of auto- (αὐτο-, “self”) and the root *men- (denoting mental activity or movement). The term historically characterized mechanical contrivances that operated via internal clockwork without continual human intervention.
The noun reinforcer stems from the verb reinforce, tracing to the Middle French reinforcer and Old French enforcier, rooted in Late Latin reinfortiare (from re-, indicating repetition or intensification, and fortis, meaning “strong”). B. F. Skinner synthesized these traditions in his seminal 1957 treatise Verbal Behavior, formally deploying the construct of “automatic reinforcement” to explain how verbal emissions, acoustic feedback, and intraverbal chains are shaped and preserved when the speaker acts simultaneously as their own listener, experiencing direct auditory consequences that strengthen behavioral repertoire without social arbitration.
3. Pronunciation & Grammatical Form
The standard International Phonetic Alphabet (IPA) pronunciation for the term in contemporary Received Pronunciation and General American English is:
- General American: /ˌɔː.təˈmæt̬.ɪk ˌriː.ɪnˈfɔːr.sɚ/
- Received Pronunciation: /ˌɔː.təˈmæt.ɪk ˌriː.ɪnˈfɔː.sə/
Grammatically, “automatic reinforcer” functions as a countable compound noun phrase (plural: automatic reinforcers). The corresponding abstract noun phrase describing the functional process or contingency is automatic reinforcement (uncountable). Clinicians and experimental researchers also utilize the adjectival derivation “automatically reinforced” to qualify functional classes of behavior (e.g., “an automatically reinforced stereotypic response”).
4. Detailed Conceptual Explanation
To fully grasp the scope and operational mechanics of an automatic reinforcer, one must delineate the four-term operant contingency: establishing operations (motoring establishing operations or motivating operations), discriminative stimuli, the behavior or response class, and the consequential stimulus change. In conventional operant paradigms, the consequence is mediated socially; for example, a child vocalizes “water,” and a parent hands them a glass, or a student displays disruption, and an instructor provides attention or issues a disciplinary time-out. In sharp contrast, automatic reinforcement operates entirely within the direct biophysical interaction between the organism’s body and its immediate sensory environment.
The critical boundary condition defining an automatic reinforcer is the non-necessity of an external social agent. When an individual engages in hand-flapping, nail-biting, thumb-sucking, hair-twirling, body-rocking, vocal humming, or scratching an insect bite, the behavioral act directly produces changes in tactile, proprioceptive, vestibular, visual, or acoustic input. If these sensory outputs increase or preserve the likelihood of that response class occurring under comparable establishing operations, the consequence constitutes an automatic reinforcer. Critically, behavior analysts emphasize that “automatic” is not synonymous with “reflexive” or “involuntary”; automatically reinforced behaviors are operant repertoires shaped by selective consequences rather than classical respondent conditioning elicited automatically by antecedent stimuli.
Furthermore, an automatic reinforcer can operate via positive or negative reinforcement pathways. Under an automatic positive reinforcement mechanism, the behavior generates an addition of sensory stimulation that serves an appetitive function—such as the shimmering visual patterns produced by rapidly waving fingers in front of a light source, or the auditory resonance generated by vocal scripting. Under an automatic negative reinforcement mechanism, the response functions to terminate, alleviate, or attenuate an aversive internal physiological state, such as scratching an itchy patch of dermatological inflammation, rubbing an aching joint, or rocking rhythmically to dampen sensory overload and nervous system hyper-arousal.
A significant conceptual boundary must be drawn between automatic reinforcement and hypothetical internal drive states. Methodological and radical behaviorists avoid conceptualizing automatic reinforcement as a vague “need for stimulation” or an unobservable psychoanalytic drive. Instead, empirical behavior analysis operationalizes the sensory product as a tangible physical stimulus change (e.g., kinematic, kinesthetic, thermal, or acoustic stimulation) that exhibits lawful functional relationships with the frequency and pattern of the target behavior.
5. Historical Development
The historical trajectory of automatic reinforcement reflects the broader evolution of behaviorism from early radical behavior analysis to modern applied behavior analysis (ABA). B. F. Skinner laid the foundational theoretical groundwork across several foundational publications. In Science and Human Behavior (1953) and most explicitly in Verbal Behavior (1957), Skinner observed that vocal speech produces immediate acoustic consequences that match or diverge from the social verbal community. When an infant babbles and produces a sound that mirrors the auditory patterns of ambient human speech, the matching acoustic properties act as an automatic reinforcer, shaping the infant’s phonological repertoire in the absolute absence of immediate external social approval.
Throughout the 1960s and 1970s, as early behavioral clinicians began treating individuals diagnosed with severe developmental delays, autism spectrum conditions, and profound intellectual disabilities, repetitive behaviors such as body-rocking, head-banging, eye-gouging, and hand-mouthing were frequently categorized under the broad descriptor “self-stimulatory behavior” or “stereotypy.” Prominent figures such as Ivar Lovaas recognized that these responses appeared uniquely resistant to social extinction, prompting early hypotheses that the sensory feedback inherent in the movements was actively maintaining them.
The methodological revolution occurred in 1982 with the landmark publication of the functional analysis methodology by Brian A. Iwata and colleagues (subsequently reprinted in 1994). Iwata, Dorsey, Slifer, Bauman, and Richman introduced an empirical framework testing four distinct environmental conditions: Social Disapproval (Attention), Academic Demand (Escape), Alone (No Social Interaction or Materials), and Play (Control). When a self-injurious or stereotypic behavior persisted across the Alone condition—in an environment devoid of social consequences, task demands, or play materials—or occurred at undifferentiated, elevated levels across all conditions, the data provided empirical confirmation that the behavior was maintained by automatic reinforcement.
Following Iwata’s paradigm, researchers such as Timothy R. Vollmer (1995) refined practical and conceptual models for identifying and treating automatically reinforced aberrant behavior. Vollmer categorized automatic reinforcement paradigms, distinguished sensory extinction from competing stimulation interventions, and advanced the science beyond viewing automatic behavior simply as a default diagnosis of exclusion.
6. Theoretical Foundations
The theoretical architecture underpinning automatic reinforcement rests on three primary pillars: radical behaviorist selectionism, neurobiological sensory processing, and motivating operations frameworks.
First, within radical behaviorism, behavior is understood as an evolutionary product selected across three levels: phylogenic (natural selection shaping the biological organism), ontogenic (selection by consequences during an individual’s lifetime through operant conditioning), and cultural. Automatic reinforcement is a prime manifestation of ontogenic selection operating via direct sensory channels. The human nervous system has evolved sensory receptors that register mechanical, thermal, visual, acoustic, and chemical inputs. When an organism interacts physically with its own anatomy or the physical environment, the resulting neurochemical cascades in sensory cortical areas reinforce the specific physical topography that yielded that precise sensation.
Second, sensory processing theories and neurobiological frameworks bridge behavioral principles with biological substrates. Repetitive sensory motor behaviors often correlate with atypical neural modulation within the basal ganglia, thalamus, and sensory cortices. For individuals with neurodevelopmental profiles such as autism spectrum disorder, the central nervous system may experience either baseline hypo-arousal or hyper-arousal. Automatic reinforcement pathways can reflect homeostatic regulation: a hypo-aroused sensory system is reinforced by behaviors that heighten tactile or proprioceptive neural firing, whereas a hyper-aroused system is reinforced by repetitive rhythmic behaviors that narrow attention and attenuate unpredictable environmental overstimulation.
Third, Jack Michael’s conceptualization of Motivating Operations (MOs)—specifically Establishing Operations (EOs) and Abolishing Operations (AOs)—provides the dynamic operational framework for understanding when automatic reinforcers exert their potent behavioral effects. Prolonged periods of sensory deprivation (e.g., sitting alone in a sterile room without enriched stimulation) serve as an establishing operation that enhances the reinforcing effectiveness of self-generated sensory stimulation and evokes stereotypic behavior. Conversely, non-contingent access to rich, matched sensory toys or ambient music serves as an abolishing operation, saturating the relevant sensory modality and dramatically reducing the evocative power of the automatic reinforcer.
7. Key Components, Types & Dimensions
Automatic reinforcers are multidimensional constructs categorized systematically by functional valence, sensory modality, and physical locus:
- Automatic Positive Reinforcement (Sensory Enrichment): Contingencies wherein the initiation of the response produces immediate, appetitive physical stimulation. The organism “gains” a preferred sensory sensation.
- Automatic Negative Reinforcement (Pain and Aversion Attenuation): Contingencies wherein the initiation of the response directly alleviates, reduces, or terminates an endogenous unpleasant sensation, physical irritation, internal pain, or aversive psychological tension.
- Proprioceptive and Kinesthetic Subtypes: Reinforcement derived from the internal sensation of muscle movement, joint compression, and body positioning. Common manifestations include toe-walking, repetitive finger posturing, and intense body swaying.
- Vestibular Subtypes: Reinforcing stimuli generated through fluid movement in the inner ear receptors, informing spatial orientation and motion. Examples include intense spinning, rocking back and forth, and repetitive jumping.
- Tactile and Somatosensory Subtypes: Reinforcement emerging from touch receptors in the skin, such as rubbing textured fabrics, skin-picking, scratching, or rhythmic tapping on surfaces.
- Auditory and Acoustic Subtypes: Direct stimulation produced by vocalizations, tongue-clicking, humming, or striking objects near the ear to generate distinct acoustic frequencies.
- Visual Subtypes: Sights generated by gazing at spinning objects, flickering hands in peripheral vision, blinking repetitively under fluorescent fixtures, or visually tracking falling particles.
- Gustatory and Olfactory Subtypes: Sensory stimulation generated by putting non-food items in the mouth (pica), licking surfaces, or smelling specific chemical or biological textures.
8. Examples & Illustrative Cases
To demonstrate the pervasive nature of automatic reinforcers across both everyday life and severe clinical pathology, consider the following detailed illustrative cases:
Case 1: The Benign Acoustic and Proprioceptive Loop in Daily Life
An adult working at an office desk habitually clicks the spring-loaded plunger of a ballpoint pen whenever engaged in deep reading. No one is present to observe or reward this behavior; in fact, colleagues find it irritating. The behavior persists because the rhythmic tactile “click” felt in the thumb muscles (proprioceptive feedback) combined with the sharp snapping sound (auditory feedback) produces direct sensory modulation that counteracts fatigue and sustains alertness. The acoustic and physical feedback functions as an automatic reinforcer.
Case 2: Automatic Negative Reinforcement in Chronic Scratching
A seven-year-old child diagnosed with atopic dermatitis frequently scratches their forearm until bleeding occurs. A functional analysis reveals that scratching rates remain consistently elevated across both attention-rich conditions and completely solitary conditions with no demands. The physiological itch sensation caused by histamine release acts as an aversive motivating operation; the physical scratching produces pain signals that temporarily override and terminate the pruritus via spinal gate-control mechanisms. The physical relief is an unmediated automatic negative reinforcer.
Case 3: Severe Self-Injurious Behavior (SIB) Maintained by Proprioceptive Feedback
A non-verbal adolescent diagnosed with profound autism spectrum disorder engages in repetitive head-directed fist-hitting. Exhaustive medical evaluations rule out active dental pain, otitis media, or neurological headaches. Standard functional analysis demonstrates that fist-to-head contact occurs at peak frequencies during the Alone condition and persists at uniform levels across attention and demand conditions. The high-impact biomechanical pressure and bone-conducted sensory vibration in the cranial region serve as powerful automatic reinforcers. Treatment requires providing a protective helmet paired with functional sensory replacement: engaging the adolescent with heavy pneumatic vibration vests and rhythmic boxing-bag punching that deliver matched proprioceptive feedback without tissue damage.
9. Measurement & Assessment
Assessing whether a target response is maintained by an automatic reinforcer requires sophisticated behavioral diagnostic methodologies designed to isolate social from non-social controlling variables. Because sensory events are often private or inextricably tied to the movement itself, the behavioral scientist must rely on systematic environmental manipulation and functional analysis:
The gold standard is the classic or brief functional analysis pioneered by Iwata et al. Clinicians systematically expose the individual to multi-element analog conditions. A response is operationally diagnosed as automatically maintained under two clear patterns: (1) if the behavior persists at elevated and undifferentiated rates across all conditions, including the enriched play condition, or (2) if the behavior persists consistently across an extended series of “Alone” or “No Interaction” conditions where all social attention, academic demands, and recreational materials are systematically withheld.
When brief functional analyses are inconclusive, clinicians implement the Extended Alone Assessment or the Repeated Alone Test. In this design, the participant is observed across consecutive alone sessions spanning multiple days. Behaviors maintained by social consequences (e.g., access to adult attention or escape from work) rapidly undergo extinction in the absence of a social audience, falling to zero levels. Conversely, behaviors maintained by an automatic reinforcer demonstrate robust stability or steady upward trends across sessions because the response-consequence contingency remains structurally intact.
Complementary assessments include the Matched Stimulus Preference Assessment. Developed to pinpoint the exact sensory dimension serving as the reinforcer, this protocol systematically presents items hypothesized to mimic the sensory properties of the behavior (e.g., flashing lights for visual stereotypy; vibrating wands for kinesthetic stereotypy; musical toys for vocal scripting) to measure whether access to the object selectively competes with and suppresses the aberrant response.
10. Applications & Practical Significance
The practical identification of an automatic reinforcer is vital across clinical psychology, pediatric behavioral intervention, special education, and neuropsychiatry. Interventions designed for socially maintained behaviors typically fail catastrophically when applied to automatically reinforced actions. For instance, putting a child in time-out or ignoring a behavior under the assumption that it seeks attention will inadvertently provide an optimal, undisturbed environment for an automatically reinforced behavior to escalate.
Applied behavior analysts employ several evidence-based clinical protocols to address problematic behaviors sustained by automatic reinforcers:
- Sensory Extinction: The response is permitted to occur, but the direct sensory consequence is physically blocked or attenuated. For example, installing thick carpet to eliminate the sound of object-dropping, placing soft padded gloves on a client to eliminate the tactile sensation of skin-picking, or using noise-canceling headphones to mask acoustic reinforcement from vocal perseveration.
- Environmental Enrichment with Matched Stimulation: Clinicians proactively provide continuous, non-contingent access to alternate toys or sensory devices that mimic the exact sensory feedback of the aberrant response (e.g., offering chewable silicone jewelry for oral stereotypy or a mini-trampoline for motor jumping). This operates as an abolishing operation, lowering the motivation to engage in the target behavior.
- Differential Reinforcement of Alternative (DRA) or Incompatible (DRI) Behavior: The individual is taught and heavily reinforced for engaging in a functionally competitive, safe motor response that renders the automatically reinforced behavior physically impossible (e.g., keeping hands inside pockets or gripping a stress ball instead of hand-wringing).
- Response Interruption and Redirection (RIRD): Upon the initiation of the automatically reinforced response (such as vocal stereotypy), the therapist immediately interrupts the chain and presents a series of effortful motor or vocal compliance demands (e.g., “Look at me,” “Touch your nose”). This introduces a temporary response cost and interrupts the completion of the sensory reinforcement cycle.
11. Research & Empirical Evidence
Empirical research investigating automatic reinforcement has progressed through hundreds of peer-reviewed clinical studies, published primarily in journals such as the Journal of Applied Behavior Analysis (JABA) and Behavioral Interventions. A seminal meta-analytic investigation by Iwata, Pace, Dorsey, et al. (1994), summarizing functional analyses across 152 individuals displaying severe self-injurious behavior (SIB), revealed that approximately 25.7% of all clinical cases were maintained exclusively by automatic reinforcement, representing the second largest single behavioral etiology after social escape.
Pioneering clinical research by Timothy Vollmer, Peter Sturmey, and Cathleen Piazza further advanced sensory modalities matching. Research by Piazza et al. (2000) demonstrated that sensory stimuli matched specifically to the sensory modality of stereotypy (such as tactile items for hand-mouthing) produced vastly superior behavioral suppression compared to unmatched, arbitrarily preferred toys. Their work established that identifying the precise sensory property of the automatic reinforcer is a non-negotiable prerequisite for successful non-aversive intervention.
A rigorous randomized controlled study on Response Interruption and Redirection conducted by Ahearn, Clark, MacDonald, and Chung (2007) transformed clinical protocols for automatically reinforced vocal stereotypy. Their empirical findings showed that vocal RIRD consistently decreased vocal stereotypy to near-zero levels while simultaneously producing significant collateral increases in appropriate functional vocal communication, proving that structured motor/vocal engagement can successfully disrupt entrenched automatic reinforcement loops without requiring restrictive sensory deprivation.
12. Cultural & Cross-Cultural Considerations
While the fundamental neurobiological mechanisms of automatic reinforcers are universal across the human species, the societal perception, clinical labeling, and behavioral tolerance of automatically reinforced responses vary significantly across cultures. In high-context, collectivist cultures where behavioral conformity, quiet decorum, and group cohesion are heavily prioritized, overt motor mannerisms maintained by automatic reinforcement (such as pacing, hand-flapping, vocal humming, or rocking) are frequently subjected to intense social stigma and immediate corrective suppression.
Conversely, in certain indigenous or spiritual traditions, repetitive rhythmic motor behaviors that generate altered physiological states—such as continuous drumming, sustained whirling, or rhythmic chanting—are culturally sanctioned, institutionalized, and actively reinforced within ritualistic communal settings. In these contexts, the proprioceptive, vestibular, and acoustic feedback of rhythmic movements is not pathologized as “stereotypy” but revered as a pathway to meditative presence or transcendence.
Furthermore, within contemporary Western societies, the rise of the Neurodiversity Movement has ignited intense cultural debate regarding how automatically reinforced behaviors are treated. Autistic self-advocates emphasize that repetitive self-stimulatory behaviors (“stimming”) serve critical emotional regulation functions, acting as an adaptive, automatically reinforcing buffer against overwhelming environmental sensory chaos. Consequently, neurodiversity-informed clinical standards increasingly demand that practitioners refrain from targeting benign automatically reinforced stimming for elimination simply to make an individual appear “neurotypical,” reserving intervention exclusively for behaviors that cause physical tissue damage or severely compromise functional independence.
13. Criticisms, Debates & Limitations
Despite its central role in operant theory, the concept of the automatic reinforcer has been the subject of longstanding methodological and philosophical debate within the behavioral sciences:
The most prominent critique centers on the danger of explanatory circularity. Critics from cognitive and experimental psychology argue that diagnosing automatic reinforcement can easily devolve into a tautological label: Why does the person flap their hands? Because it is automatically reinforcing. How do we know it is automatically reinforcing? Because they flap their hands in an empty room. Without directly measuring the neurobiological or sensory feedback event independently of the physical movement, the construct risks becoming a descriptive placeholder rather than an explanatory cause.
A second major limitation involves the ethical and practical difficulty of implementing genuine “sensory extinction.” Unlike social reinforcement, where a teacher or parent can simply be instructed to withhold social praise or cease granting escape, sensory feedback is inherently wired into the nervous system. Completely eliminating the auditory feedback of a voice or the tactile sensation of skin-rubbing is technically daunting, often requires physically intrusive or restrictive apparatuses (e.g., padded helmets, eye goggles, acoustic barriers), and carries a high risk of triggering an extinction burst characterized by extreme emotional distress.
Finally, researchers acknowledge that the automatic reinforcement classification can serve as an oversimplified umbrella that obscures complex, heterogeneous internal biomedical events. Behaviors identified as automatically maintained may in reality be driven by undiagnosed physiological pain (e.g., gastrointestinal reflux, sinus inflammation, subclinical dental abscesses). Failing to thoroughly explore medical and somatic variables prior to concluding that a behavior is simply an operant sensory habit risks leaving painful medical conditions untreated under the assumption of “sensory stimulation.”
14. Related Terms & Distinctions
To ensure diagnostic and conceptual clarity, automatic reinforcers must be distinguished from closely related behavioral and psychological phenomena:
- Socially Mediated Reinforcement: Consequences delivered through the deliberate action of another living organism (e.g., a teacher giving a sticker, an adult speaking). Distinction: Automatic reinforcement is delivered immediately and solely by the physical mechanics of the response without interpersonal mediation.
- Intrinsic Motivation: A cognitive construct describing the internal satisfaction, joy, or perceived autonomy derived from performing an activity for its own sake. Distinction: While intrinsically motivated behaviors may involve automatic reinforcers, intrinsic motivation relies on mentalistic, cognitive-evaluative frameworks, whereas automatic reinforcement is an empirically verified, selectionist operant contingency.
- Reflexes (Respondent Conditioning): Involuntary, unlearned physiological reactions elicited instantaneously by antecedent stimuli (e.g., the patellar tendon reflex). Distinction: Automatically reinforced responses are operant behaviors shaped by subsequent consequences, whereas reflexes are elicited responses controlled by antecedents.
- Sensory Extinction: The behavioral procedure of decoupling a behavior from its inherent sensory consequence by physically dampening or terminating the sensory feedback. Distinction: Sensory extinction is the clinical intervention used to neutralize an automatic reinforcer.
- Stereotypy: Repetitive, invariant, and non-functional motor or vocal topographies common in neurodevelopmental profiles. Distinction: Stereotypy is a descriptive classification of behavioral topography, whereas automatic reinforcement identifies the maintaining functional mechanism behind many stereotypic responses.
15. Summary / Key Takeaways
An automatic reinforcer represents a vital concept in the experimental and applied analysis of behavior, demonstrating that operant conditioning is not confined to the social arena. The primary principles governing automatic reinforcement include:
- Automatic reinforcers are direct, non-socially mediated sensory consequences produced immediately by a behavioral response that strengthen its future probability.
- They operate through both positive reinforcement (gaining appetitive sensory, vestibular, kinesthetic, acoustic, or visual input) and negative reinforcement (alleviating internal physiological pain, itch, discomfort, or overstimulation).
- They were theoretically established by B. F. Skinner in 1957 and operationally standardized within functional analysis methodology by Brian Iwata and colleagues in 1982.
- Behaviors sustained by automatic reinforcement persist across Extended Alone conditions and are unresponsive to traditional social extinction protocols.
- Contemporary interventions focus on humane, non-aversive modalities: introducing environmental enrichment with matched sensory properties, abolishing operations, and response redirection, while respecting neurodivergent sensory regulation needs.
In synthesis, the automatic reinforcer demonstrates the profound plasticity of behavior in response to direct bodily feedback. By recognizing that physical sensations themselves act as powerful consequences, behavior analysts can accurately assess, understand, and construct humane, effective supports for individuals navigating complex sensory environments.
References
- Ahearn, W. H., Clark, K. M., MacDonald, R. P., & Chung, B. I. (2007). Assessing and treating vocal stereotypy in children with autism. Journal of Applied Behavior Analysis, 40(2), 263–275. https://doi.org/10.1901/jaba.2007.30-06
- Iwata, B. A., Dorsey, M. F., Slifer, K. J., Bauman, K. E., & Richman, G. S. (1994). Toward a functional analysis of self-injury. Journal of Applied Behavior Analysis, 27(2), 197–209. (Reprinted from Analysis and Intervention in Developmental Disabilities, 2, 3–20, 1982). https://doi.org/10.1901/jaba.1994.27-197
- Iwata, B. A., Pace, G. M., Dorsey, M. F., Zarcone, J. R., Vollmer, T. R., Smith, R. G., Rodgers, T. A., Lerman, D. C., Shore, B. A., Jembere, E., Maglieri, K. A., & Willis, K. D. (1994). The functions of self-injurious behavior: An experimental-epidemiological analysis. Journal of Applied Behavior Analysis, 27(2), 215–240. https://doi.org/10.1901/jaba.1994.27-215
- Piazza, C. C., Adelinis, J. D., Hanley, G. P., Goh, H. L., & Delia, M. D. (2000). An evaluation of the effects of matched stimuli on behaviors maintained by automatic reinforcement. Journal of Applied Behavior Analysis, 33(1), 13–27. https://doi.org/10.1901/jaba.2000.33-13
- Skinner, B. F. (1957). Verbal Behavior. Copley Publishing Group. https://www.worldcat.org/title/verbal-behavior/oclc/490898
- Vollmer, T. R. (1995). Prevention of severe behavior problems in people with developmental disabilities. Journal of Applied Behavior Analysis, 28(4), 457–461. https://doi.org/10.1901/jaba.1995.28-457