Notes on the Current Diversification of Behaviorism
Abstract and Overview
The article by Sho Araiba examines how behaviorism has diversified beyond B. F. Skinner’s radical behaviorism and asks what factors have driven this diversification. It argues that behaviorism, as a philosophy of psychology and as a family of related approaches, has evolved through adaptive radiation: a single ancestral “species” (radical behaviorism) migrates into multiple niches (fields like clinical psychology, education, behavioral economics, philosophy of science, etc.) and experiences niche-specific selective pressures. A central focus is the agent problem: the traditional agent-free stance of radical behaviorism has faced sustained criticism and selective pressure as behaviorists move into new niches where the causal role of an agent (mind, memory, cognitive states, etc.) becomes strategically useful for explaining and predicting behavior in context. The paper uses an evolutionary biology analogy to explain diversification and stresses that niches, resources, and competition shape which forms of behaviorism survive and thrive. The discussion links historical shifts in psychology with contemporary variants of behaviorism and emphasizes pragmatism and the adaptive value of theory in changing environments. A key idea is that diversification reflects the satisfaction of niche-specific demands for explanation, prediction, and practical impact, rather than a universal drift away from foundational principles.
Adaptive Radiation: Niches, Resources, and the Evolutionary Analogy
Adaptive radiation describes the emergence of multiple species from a single ancestry due to differences in environment (niches), resource availability, and competition. The article uses this biological metaphor to understand how behaviorism diversified as it moved into different practice areas. An iconic example is Darwin’s finches: a single ancestral finch on the Galapagos Islands diversified into 13 species with varied beak shapes and diets as they colonized different islands. In behavior analysis, Skinner’s radical behaviorism is treated as the ancestral species, and as it migrates to new niches, selective pressures in those niches (e.g., the demand for handling subjective experience, cognitive processes, or social-psychological explanations) push it to adapt. In this analogy, a niche is a field of practice (e.g., experimental psychology, applied behavior analysis, education, behavioral economics, philosophy of science), while resources are the rewards and incentives (financial rewards, reputation, career advancement, social interaction, scientific discovery, etc.) that sustain a given niche. Competition among niches and the demands of the niche’s audience shape which forms of behaviorism persist and which are replaced or modified. The article also emphasizes that the diversification process is not random but is constrained by core characteristics that remained advantageous (e.g., a focus on behavior, empirical rigor, a pragmatic orientation) and by characteristics that faced selective pressure (notably the agent-free stance).
The author situates radical behaviorism as a member of the ancestral niche (experimental analysis of behavior and applied behavior analysis) with an emphasis on an atheoretical, agent-free account of behavior. As radical behaviorism encountered cognitive psychology, social psychology, and neuropsychology—fields that emphasize cognitive states and internal processes—the niche offered selective pressures that favored theories capable of integrating or acknowledging the agent (memory, cognitive states, etc.) without abandoning empirical rigor. The article cites examples of niche actors describing the clinical psychology niche, the cognitive revolution, and the presence of computational and theoretical work as evidence of the adaptive pressures shaping diversification.
Table 1: List of Behaviorisms and Their Characteristics (Overview)
The article presents Table 1 as a catalog of behaviorisms developed after Skinner’s radical behaviorism and summarizes their key traits. The major rows include radical behaviorism, emergent behaviorism, theoretical behaviorism, teleological behaviorism, multiscale behaviorism, molar multiscale view, intentional behaviorism, and contextualistic behaviorism. Each row lists the key proponent(s), year(s), field of practice, subject matter, whether the approach is atheoretical, whether it is empirical, whether it is pragmatic, and what counts as the agent in that approach.
Radical Behaviorism (Skinner, Moore, Catania, Palmer) — 1945 — Field: Experimental Analysis of Behavior, Applied Behavior Analysis — Subject matter: Animal and human behavior — Atheoretical: Yes — Empirical: Yes — Pragmatic: Yes — Agent: N/A
Emergent Behaviorism (Killeen) — 1984 — Field: Learning theory, Cognitive Psychology, Neuropsychology — Subject matter: Animal and human behavior and cognition — Atheoretical: No — Empirical: Yes — Pragmatic: Yes — Agent: Cognition
Theoretical Behaviorism (Staddon) — 2001, 2017 — Field: Learning theory, Cognitive Psychology, Neuropsychology — Subject matter: Animal and human behavior and cognition — Atheoretical: No — Empirical: Yes — Pragmatic: Yes — Agent: State
Teleological Behaviorism (Rachlin) — 1994 — Field: Experimental Analysis of Behavior — Subject matter: Animal and human behavior — Atheoretical: Yes — Empirical: Yes — Pragmatic: Yes — Agent: Organism as a whole
Multiscale Behaviorism (Hineline, Shim) — 2001 — Field: Experimental Analysis of Behavior — Subject matter: Animal and human behavior — Atheoretical: Yes — Empirical: Yes — Pragmatic: Yes — Agent: N/A
Molar Multiscale View (Baum) — 2002 — Field: Experimental Analysis of Behavior — Subject matter: Animal and human behavior — Atheoretical: Yes — Empirical: Yes — Pragmatic: Yes — Agent: N/A
Intentional Behaviorism (Foxall) — 2007 — Field: Behavioral economics / Consumer psychology — Subject matter: Human behavior and subjective experience — Atheoretical: No — Empirical: Yes and No — Pragmatic: Yes — Agent: Person
Contextualistic Behaviorism (Hayes & Hayes) — 1992 — Field: Psychotherapy — Subject matter: Human behavior — Atheoretical: Yes — Empirical: Yes — Pragmatic: Yes — Agent: Organism as a whole
These entries illustrate how subsequent behaviorisms maintain some shared commitments (e.g., emphasis on behavior and pragmatism) while diverging in their stance toward the role of the agent, the level of theoretical commitments, and the emphasis on empirical adequacy. The table also highlights how “agent” status varies: some approaches keep an explicit agent (e.g., the person or organism as a whole), while radical and molar/multiscale variants tend to reduce or reframe agent involvement.
The Agent Problem: Definition, Origins, and Strategic Pressures
A central theme of the article is the agent problem: behaviorism’s traditional stance minimizes or denies an independent causal “agent” (mind, cognition, personality, perception, emotion, physiology) as the driver of behavior. The author defines the agent as a hypothetical entity present across time and environments that can change behavior according to differences in time and settings. Kantor’s perspective (1933, 1963) framed behavior as a complete body action — a total neuro-musculo-glandular configuration — arguing that the S-R formulation rejects the existence of an agent as an isolated causal factor. This agent-free stance is a defining characteristic of radical behaviorism, including Skinner’s three-term contingency, which treats the organism as the medium rather than a separate causal agent. The article notes that many psychology-related niches demand attention to an agent (mind, cognition, personality, etc.), and other domains (education, economics, entertainment) assume some form of agentive causation. Over time, radical behaviorism faced persistent criticism from outside its niche (e.g., Bandura’s social learning critique; Chomsky’s linguistics critique) that invoked cognitive processes and private events as necessary to explain behavior, language, and social behavior. In response, various modern behaviorisms have either integrated agent-like constructs (as hypothetical states or cognitive processes) or reframed private events and internal variables as aspect of a broader system, rather than as isolated causal factors. The agent problem thus acts as a selective pressure: in niches that reward accounting for subjective experience, motivation, memory, or cognitive processing, behaviorists are compelled to adjust their models to remain viable and scientifically credible.
The Origin of Behaviorism: Watson, Kantor, Pavlov, and the Early Fight Over the Agent
The article traces the origin of behaviorism to Watson’s 1913 manifesto in experimental psychology, which found favor because it aligned with a demand for a hard science of psychology. Watson emphasized the reaction of the whole animal to a given stimulus and treated the stimulus–response relation as a complete, independent phenomenon, rejecting mental or brain-based interpretations. Pavlov’s conditioned reflex work (Pavlov, 1927/1960) influenced Skinner’s later advocacy for an empirical, observable-behavior focus, but Kantor (1933) argued that behavior is a complete body action, a total organism configuration, and rejected the idea that an agent could serve as an isolated cause of behavior. This rejection laid the groundwork for radical behaviorism’s agent-free stance: the S-R model could explain behavior without invoking internal causes. The early success of behaviorism depended on the community’s preference for rigorous, observable phenomena and a push away from unobservable mind states. However, as cognitive psychology and related fields rose in prominence, the “agent” re-entered the scientific scene in various forms, challenging the conventional agent-free account and pushing behaviorists to adapt to maintain credibility and relevance in new scientific communities.
Mainstream Experimental Psychology and the Return of the Agent: The Cognitive Revolution and Its Aftermath
While radical behaviorism dominated certain experimental niches, mainstream experimental psychology gradually embraced cognitive approaches and the intervening variables (S–O–R formulations) that reintroduce agent-like constructs (memory, attention, internal states). Hull, Spence, and Tolman contributed to the S–O–R framework by recognizing organismic variables (O) that mediate between stimuli and responses, which in turn fed the cognitive revolution. This shift placed cognitive psychology and related disciplines in more favorable positions to explain behavior through internal processes, thus reducing the long-term attractiveness of a purely agent-free radical approach. In response, some behaviorists adapted by developing emergent behaviorism (Killeen, 1984) and theoretical behaviorism (Staddon, 2001, 2017), which integrate cognitive processes or hypothesized states into a broader theoretical framework while maintaining empirical rigor. These adaptations retain Skinnerian commitments to empiricism, pragmatism, and an emphasis on behavior while acknowledging the necessity of additional constructs (e.g., memory, state) to account for behavior across varied conditions. The debate around the role of the agent thus shifted from an outright rejection to a more nuanced acknowledgment of agent-like constructs as part of a larger system that still seeks to minimize unnecessary postulation of unobservable inner causes.
Emergent Behaviorism and Theoretical Behaviorism: Adding an Agent to the Picture
Emergent behaviorism (Killeen, 1984) argues that cognitive processes are not reducible to simple reflexive chains and that cognitive processes can be studied as part of a causal chain linking stimulus and response. It treats cognition as a component that emerges in a causal sequence, not as a separate causal agent. Theoretical behaviorism (Staddon, 2001, 2017) similarly expands the framework to include constructs like a behavioral state or repertoire, which can vary across environments and time. Both approaches employ a hypothetico-deductive method to study behavior and reject radical behaviorism’s atheoretical stance while preserving empirical rigor and a pragmatic orientation. They assume the presence of an agent (e.g., memory or a state) as part of the explanation, thereby reconciling the need for internal variables with the demand for observable data and testable predictions. In these frameworks, Skinner’s three-term contingency is not treated as a standalone, isolated mechanism; instead, it sits within a larger system in which actor states, cognitive processes, or other intermediate variables influence how stimuli produce behavior. The agent is not denied, but its role is reframed as a variable within a comprehensive, theory-driven account of behavior that can generalize across conditions and species. These shifts reflect selective pressures in the mainstream experimental psychology niche, which rewards theory-building and prediction across multiple settings and times while remaining compatible with empirical data.
The Molars, Moles, and Private Events: How Different Schools Handle the Agent
The debate about agent-free analysis extends to private events and private mental states. Radical behaviorists initially denied private events as causal agents, opting for observable behavior and functional relations. Over time, debates around private events led to different responses. Some, like Baum, argued that private events are not necessary for a science of behavior and can be understood via functional contingencies in observable behavior. Others argued for including private events as part of a broader, more comprehensive account that still maintains a disciplined, empirical approach. The discussion about private events reflects broader tensions about whether to retain a strictly agent-free analysis or to incorporate hypothetical internal states as functional variables that can be scientifically studied, measured, and tested. The shift toward a four-term contingency in applied behavior analysis (ABA), which includes Motivating Operations (MOs) or Establishing Operations (EOs) in addition to the antecedent, behavior, and consequence, exemplifies this trend. The four-term contingency recognizes that internal states (e.g., motivation, drive) can modulate the effectiveness of environmental stimuli, thereby complicating the simple A→B→C account while avoiding positing a mysterious inner agent. The motivation literature traces the evolution from initial environmental drives to formal MO/EO concepts introduced by Skinner, Michael, and Sundberg, and later extended in ABA. The four-term model remains agent-free in the sense that it explains behavior via environmental interactions and operation-based drives rather than invoking a disembodied mind as the causal agent, but it introduces a more nuanced role for internal states as variables that influence the contingencies themselves.
Radical Behaviorism in Applied Behavior Analysis: Practical Adaptations and New Contingencies
Applied Behavior Analysis (ABA) has historically aligned with radical behaviorism’s focus on observable behavior and contingencies, but the clinical and educational settings it serves have created pressures to account for subjective experience and personal relevance. Baer, Wolf, and Risley (1968) argued that small changes in behavior could be practically significant even if they seem modest in controlled settings, emphasizing the practical importance of behavior-change in real-world contexts. In clinical practice, therapists and families value subjective experience and personal meaning; thus, the niche’s selective pressures reward techniques that demonstrate social validity, appeal to laypeople, and translate technical language into accessible terms. Consequently, while ABA maintains the agent-free stance at its core, it has adopted extensions to the three-term contingency to address motivational factors and genetic influences without fully recapitulating a cognitivist or agent-centered framework.
Two notable extensions discussed are the treatment of motivation and genetics. The literature on motivation in ABA traces back to Skinner’s early use of drives as internal states, which Skinner later externalized as environmental operations (e.g., food deprivation manipulated to influence the reinforcing effectiveness of outcomes). Michael (1982, 1993) introduced “motivating operations” (MOs) as variables that influence the value of consequences and the likelihood of a behavior occurring. Sundberg (1993) proposed reconceptualizing the three-term contingency as a four-term model: Motivating Operation, Antecedent, Behavior, and Consequence. While these extensions are operationally sound, their inclusion implies an agent-like state that modulates the effectiveness of environmental stimuli. This is the point at which ABA’s agent-free stance faces tension: to maintain empirical rigor and avoid speculative internal causality, the literature frames these variables as environmental operations or generalized behavioral properties rather than as true mental states or internal agents.
Langthorne and McGill (2008) argued for incorporating genetic factors into early development models of self-injurious behavior (SIB) for individuals with developmental disabilities. They proposed expanding analysis to include gene–environment interactions that influence motivation, topography, and contingencies that sustain SIB. They emphasize that acknowledging genetic influence can improve assessment, treatment, and prevention, yet doing so arguably introduces a state-like variable that would be difficult to explain purely in terms of external contingencies. Breland and Breland (1961) also highlighted the necessity of considering instinctive and species-specific patterns when conditioning behavior in animal training, urging practitioners to study animals ethnologically and holistically. These discussions underscore a recurring theme: the agent problem is persistent in real-world applications, and practitioners must adapt their models to maintain effectiveness and social relevance without surrendering the agent-free philosophical commitments of radical behaviorism.
Applied behavior analysis thus demonstrates how the agent problem informs practice: practitioners translate theoretical terms into lay explanations, expand contingencies to account for motivational and genetic factors, and emphasize socially meaningful outcomes and practical effectiveness. The result is a spectrum of approaches that preserve radical behaviorism’s emphasis on observable behavior and environmental control while accommodating niche-specific demands and the real-world complexity of human behavior.
Human Behavior and Behaviorism: Intentional and Contextualistic Responses to the Agent
The article discusses two notable branches focused on human behavior in niches where the agent becomes central: intentional behaviorism and contextualistic behaviorism. Intentional behaviorism, advanced by Foxall (2007, 2008), embraces the agent by incorporating intentional explanations and first-person reports (intentional idioms) into the analysis of consumer behavior and economics. Foxall argues that radical behaviorism misses important information at the personal level (subjective experience) and that intentional behaviorism seeks to bridge external stimulus–consequence relations with personal experience through intentional terms. The approach allows a person to mediate time and environments and emphasizes subjective experience as an indispensable part of the analysis, particularly in human economics and consumer behavior. In intentional behaviorism, the agent is not just a hypothetical construct but a mediator between environmental events and behavior, expressed through language and self-report. This is a drastic move away from agent-free rigor but is motivated by niche demands for practical understanding of human behavior in everyday contexts.
Contextualistic behaviorism (Hayes & Hayes, 1992) takes a different route. It reframes psychological analysis as the study of whole organisms interacting in and with a context, emphasizing the organism in its environment rather than isolating internal processes. It challenges the mechanistic critique of cognitive therapy and other forms of mechanistic behavior therapy that focus on isolated cognitive components. Contextualism aims to be palatable to clinical workers who value cognitive explanations while preserving Skinnerian functional approaches. The contextualistic stance argues that the subject matter is not merely isolated cognitive processes but the organism’s behavior within a complex network of contextual factors. The two approaches converge on the view that human behavior requires attention to the agent (or organism) and its subjective experience to explain and predict behavior effectively in real-world settings. They differ in whether they explicitly include the agent as a central causal factor (intentional behaviorism) or treat the agent as part of the organism within a broader context (contextualistic behaviorism).
The article highlights competition within each niche: contextualistic behaviorism competes with cognitivist approaches in clinical psychology, whereas intentional behaviorism aligns with economic and consumer-behavior niches that value personal experience and intentional explanations. These niches demand different kinds of justification for theory and practice, which explains why similar subject matter—human behavior in complex environments—gives rise to distinct, sometimes competing, versions of behaviorism.
Pragmatism and Diversification: The Practical Imperative Driving Multiple Paths
Pragmatism is presented as a defining feature of behaviorism’s adaptability. The author notes that behaviorism’s pragmatic success in changing behavior has allowed it to flourish in diverse niches, including clinical psychology, economics, education, and philosophy of science. Pragmatism makes it easier to accept new concepts, methods, and extensions as long as they yield practically useful predictions and interventions. This openness to methodological pluralism helps explain why a family of related approaches—emergent, molar, teleological, molar multiscale, intentional, contextualistic, and others—have emerged and persisted. However, pragmatism also invites debate about what should count as the subject matter, how to measure outcomes, and how to interpret results across different contexts. Some scholars worry that excessive diversification can hinder scientific communication and critique, potentially destabilizing a shared framework for evaluating behavior-analytic research. Critics like Staddon (2018) warn that diversification can undermine coherent scientific dialogue across niches, while others (Rider, 1991) note the risk of reduced communication between experimental and applied analyses. Proponents argue that diversification is a natural response to changing environments and essential for the survival and relevance of behaviorism in various fields. The tension between pragmatism and theoretical unity thus remains a live issue in the ongoing evolution of behaviorism.
Conclusion: Diversification as Adaptive Radiation and the Agent Problem
The article concludes that the diversification of behaviorism over recent decades can be understood as adaptive radiation in response to niche-specific selective pressures. As behaviorism migrated from its original niche (experimental psychology) into new niches (clinical psychology, education, behavioral economics, philosophy, etc.), it diversified into a family of approaches that retained core features (emphasis on behavior, empirical orientation, pragmatism) while modifying or reinterpreting other characteristics (notably the agent-free stance). The agent problem emerges as a central selective pressure that shapes new forms of behaviorism: different niches demand different treatments of the agent, memory, cognition, and subjective experience. The presence of competitors and the availability of resources in each niche contribute to which forms survive and how they articulate their subject matter. The article emphasizes that diversification is a natural, adaptive response to environmental demands, and time will reveal which forms of behaviorism endure as the dominant or most useful for future practice. The conclusion underscores the pragmatist impetus behind diversification: behaviorism survives by successfully altering its shape to fit the niche while maintaining its fundamental commitments to empirical evidence, methodological rigor, and pragmatic outcomes.
Key Concepts, Formulas, and Representative Points
Three-term contingency (Skinner’s core): where Antecedent, Behavior, and Consequence form a functional relation.
S-R vs S-O-R framing: Stimulus → Organism (including state) → Response, with organismic variables mediating the relation; often extended to include a Consequence in an S-O-R-C framework.
Four-term contingency (motivating operations): or , where Motivating Operations or Establishing Operations modulate the value or probability of the consequences.
Emergent behaviorism (Killeen, 1984): posits cognitive processes as part of a causal chain that can be studied scientifically via hypothetico-deductive methods; maintains an agent-based component (e.g., memory) as part of a larger system.
The molar multiscale view (Baum, 2002): analyzes behavior across multiple time scales, treating time and activity chains as units of analysis rather than single, momentary responses; emphasizes time and aggregated patterns to explain behavior without invoking an isolated agent.
Teleological behaviorism (Rachlin, 1994, 2013): emphasizes overt behavior over time within a person’s social and temporal context, treating mental life as residing in overt behavior; includes intentional explanations in some contexts.
Contextualistic behaviorism (Hayes & Hayes, 1992): views psychology as the study of organisms interacting in and with their contexts; emphasizes the organism-context relationship rather than isolated cognitive processes.
Intentional behaviorism (Foxall, 2007, 2008, 2017): integrates intentional language and personal experience into behavior analysis, especially in consumer behavior and economics; treats the agent as a mediator between environment and behavior.
Pragmatism in behaviorism: the idea that theory should yield practical, behaviorally relevant outcomes in diverse niches; diversification is a pragmatic response to real-world demands.
Representative examples and terms:
Darwin’s finches as an illustrative case of adaptive radiation and specialization of niches.
The agent problem as a persistent source of tension between agent-free traditions and niche expectations for explaining subjective experience, motivation, memory, and cognition.
The role of private events in radical behaviorism: initial operational definitions reframed private events as functions of contingencies rather than as causes.
Motivating operations (MOs) and establishing operations (EOs) as refinements to the three-term contingency to account for variability in motivational states across environments.
The interaction of genetics with behavior in applied settings (e.g., self-injury in developmental disabilities) as a case for situating behavior within a broader etiological system without abandoning empirical methods.
Real-world relevance and ethical implications:
The diversification of behaviorism reflects the need for theories to address clinically relevant outcomes, educational effectiveness, and socially meaningful changes in behavior.
Integrating subjective experience in intentional behaviorism raises questions about privacy, autonomy, and the ethical use of self-report data in behavioral interventions.
Emphasizing pragmatic success must be balanced with scientific rigor and ongoing scrutiny of how well different approaches generalize across populations and settings.
Connections to foundational principles and real-world relevance:
The move from a strict agent-free stance to agent-inclusive models mirrors broader scientific shifts toward integrating internal states when they enhance predictive power and practical usefulness.
The adaptive radiation framework provides a unifying lens for understanding why multiple, sometimes competing, formulations of behavior analysis exist today, each tailored to a sector (clinical, educational, economic, philosophical).
Formulas and equations to remember:
Three-term contingency:
S-R and S-O-R conceptualizations (schematic):
Four-term contingency ( motivating operations):
Distinction between molecular vs molar analyses: Molecular analyzes a single occurrence of a response; Molar analyzes aggregates of responses across time.
Takeaway themes for exam preparation:
Behaviorism has diversified through adaptive radiation as it moved across niches, with the agent problem as a central driver.
Different branches (emergent, theoretical, teleological, molar, contextualistic, intentional) offer distinct ways to maintain empirical grounding while addressing niche demands.
The balance between agent-free commitments and practical necessity to model subjective experience shapes contemporary behavior-analytic theory and practice.
Practical applications in ABA illustrate how theory translates into clinical and educational interventions, while also highlighting ongoing debates about how to incorporate genetic, motivational, and cognitive variables without sacrificing core principles.
References and Contextual Notes
The article cites classic and contemporary sources across behaviorism and adjacent fields, including Skinner (1945, 1957, 1938/1990), Bandura (1986), Chomsky (1959), Kantor (1933, 1963), Watson (1913, 1930/1957), Pavlov (1927/1960), and many others. The discussion is anchored in a long-running debate about whether behavior should be understood strictly through environmental contingencies or through a broader framework that includes cognitive, motivational, and situational factors.
The narrative frames diversification as a possible sign of healthy scientific evolution or as a potential hazard if it undermines cross-niche communication and critical exchange, a tension reflected in debates among scholars such as Staddon (2018) and Rider (1991).
Notable recurring themes include: the agent problem as a selective pressure; the role of niche-specific rewards and competition; the balance between theory-building, empirical testing, and pragmatic impact; and the ongoing negotiation between formalism and interpretive explanations in human behavior.