Guest blog authored by Michael Passage
The (Usual) Origin Story of Radical Behaviorism
When students first encounter the science of behavior, they are usually introduced to a handful of familiar names from the late nineteenth and early twentieth centuries. Pavlov. Watson. Thorndike. Skinner. The story often begins with the emergence of experimental psychology and the rejection of introspection as a scientific method and ends with the philosophy of B. F. Skinner’s radical behaviorism.
But beginning there skips something important.
If we start our story with Skinner, it may appear that radical behaviorism emerged from methodological reform. If we begin with American pragmatists like William James, we may conclude that the philosophical commitments associated with radical behaviorism are uniquely American. By beginning with Darwin, we risk treating selection as the primary organizing principle, thus overshadowing other important constraints.
By the time Skinner developed radical behaviorism, constraints to the following questions had already been established:
- Does behavior belong to the natural world
- Are behavioral events lawful?
- Does knowledge require systematic observation?
- Can the mind be a legitimate explanatory entity?
Therefore, we will begin our story in ancient Greece, where many of the core conceptual tensions that shaped Western philosophy were first systematically articulated. From there, we will discuss eight constraints, or, as I call them, philosophical pillars of radical behaviorism.
The Philosophical Pillars of Radical Behaviorism
A philosophical pillar is a load-bearing commitment that constrains explanation. It limits what counts as acceptable and dictates which options are ruled in or out. Essentially, they shape the radical behaviorist’s understanding of behavior.
Some pillars directly influenced Skinner. That is, he was explicitly trained in the traditions of the philosophical predecessor. Think Darwin, a name commonly referenced in Skinner’s written work. Skinner did not merely cite Darwin as historical background; he adopted natural selection as a model for understanding behavior itself, extending variation and selection from the biological level to operant conditioning and later to cultural practices. In this way, Darwin’s framework was an explanatory template that shaped Skinner’s conceptualization of the emergence, maintenance, and modification of behavior.
Other pillars exert indirect influence on Skinner’s development of radical behaviorism. They formed part of a broader scientific environment that defined what kinds of explanations were acceptable in the twentieth century. Naturalism is a clear example. By the time Skinner began writing, explaining phenomena in purely natural terms was already firmly established within the sciences. He did not need to argue that behavior belonged to the natural world; that constraint was already in place, quietly shaping what counted as a legitimate explanation.
I have identified eight philosophical pillars that I believe are foundational to radical behaviorism. These eight are not meant to be exhaustive. Rather, they represent the core, recurring constraints that have shaped the science of behavior. These include:
- Naturalism: the commitment that the phenomena we study belong to the natural world and must be explained in natural terms.
- Monism: the rejection that reality is divided into fundamentally different substances.
- Determinism: the commitment that events occur according to lawful relations rather than uncaused spontaneity.
- Empiricism: the constraint that knowledgeable claims must be grounded in systematic observation and interaction with the world.
- Materialism and Physicalism: the commitment that everything that exists belongs to the physical world as described by our best scientific explanations.
- Pragmatism: the constraint that scientific explanations are judged by how well they help us predict and influence the world, rather than by whether they claim to uncover some ultimate or hidden truth about reality.
- Contextualism: emphasizes that events must be analyzed in relation to the historical and environmental contexts in which they occur.
- Selectionism: the commitment that complex patterns are explained by variation and differential retention over time, rather than by design or intention.
Why did these ideas survive, while others did not?
Throughout history, alternative views have been available, but they have withered away on the vine. Conversely, some views proved more productive for scientific inquiry and were thus retained and refined. Understanding how these pillars endured requires examination of the problems they solved and the intellectual environments in which they were selected.
The Lineage Diagram
Below is a lineage diagram illustrating major philosophical contributions to radical behaviorism. Each column represents a distinct philosophical pillar, with figures arranged chronologically. Solid lines indicate relatively direct intellectual transmission, such as explicit engagement with a predecessor’s work, identifiable doctrinal inheritance, or clear adoption and development of specific ideas. Dotted lines indicate indirect influence. These reflect cases in which a thinker did not formally derive their position from a predecessor but was shaped by ideas that had already circulated within the broader intellectual or scientific culture. When no connecting line appears between figures, it indicates that the thinker is included within the pillar for conceptual relevance but is not presented as part of a traceable transmission lineage. In such cases, the contribution is foundational, parallel, or structurally analogous rather than genealogically continuous. The diagram is not exhaustive. It highlights figures who significantly redirected the trajectory of a given pillar, rather than cataloging every contributor within each tradition.
Future Blog Posts
Going forward, each subsequent blog post will examine one pillar in depth, tracing its historical development and clarifying its relevance to radical behaviorism. Some pillars have long, complex histories, such as determinism and empiricism, which span millennia of debate. Others, such as contextualism and selectionism, are more recent but not less important.
Furthermore, I hope to send you further down the rabbit hole with me by recommending books, podcasts, documentaries, and films that illuminate these philosophical commitments.
Closing
Radical behaviorism is not merely a set of methods. It is a philosophical position constrained by commitment that long predate the discipline. These constraints, or pillars, are explicit and clarify the science of human behavior. In the blog posts that follow, I invite you to trace these pillars with me and examine how they have shaped, and continue to shape, the science of human behavior.