What Are Private Events?
In behavior analysis, private events are behaviors and stimuli that occur within the skin of the individual and are therefore accessible only to that person. They include thoughts, feelings, sensations, images, and other covert experiences. The defining feature of a private event is not that it is "mental" or nonphysical, but that it is observable by only one person: the individual who experiences it. This distinction between public and private is one of accessibility, not of substance.
B.F. Skinner addressed private events extensively in his 1953 book Science and Human Behavior and in subsequent works. His position, which defines radical behaviorism, was that private events are real physical events that follow the same behavioral principles as public behavior. They are not causes of behavior but rather additional behaviors to be explained by the same environmental variables that explain overt actions.
The Radical Behaviorist Position
Private Events as Behavior
Radical behaviorism holds that private events are behavior. Thinking, for example, is behaving. When you silently "talk to yourself," you are engaging in covert verbal behavior that follows the same principles as overt verbal behavior. The difference is only in scale: covert verbal behavior is simply overt verbal behavior that has been reduced in magnitude to the point where it is no longer detectable by others. This is sometimes called "subvocal speech" and has been supported by research showing muscular activity in the speech apparatus during silent thinking.
Not Causes, but Part of the Causal Chain
A critical point in the radical behaviorist analysis is that private events are not the causes of public behavior; they are part of the same causal chain. When someone says "I hit him because I was angry," the radical behaviorist does not accept anger as a cause of hitting. Instead, both the anger (a private event involving physiological arousal and covert verbal behavior) and the hitting (a public behavior) are effects of the same environmental variables. Perhaps a provocation (an environmental event) produced both the anger response and the aggression. The anger did not cause the aggression; the environmental event caused both.
This is one of the most commonly tested aspects of radical behaviorism on the BCBA exam. The error of treating private events as causes is called mentalism or the explanatory fiction. When a clinician says a child hits because he is angry, they have provided a circular explanation that does not advance our understanding. The real question is: what environmental variables produce both the anger and the hitting?
Contrasting with Methodological Behaviorism
It is important to distinguish radical behaviorism from methodological behaviorism on this point. Methodological behaviorism (associated with Watson) excludes private events from scientific study because they cannot be publicly observed. Radical behaviorism includes private events as legitimate subject matter but insists on environmental explanations for them. This is a key philosophical distinction that appears on the BCBA exam.
How We Learn to Tact Private Events
One of the most interesting questions Skinner addressed is: how does a person learn to label their private events? The verbal community (the people around us) teaches us to tact our feelings and thoughts, but they face a unique problem. When teaching a child to say "red," the verbal community can see the red object and reinforce the correct response. When teaching a child to say "I'm sad," the verbal community cannot directly observe the private event (sadness) and must rely on indirect evidence.
Skinner identified four ways the verbal community teaches private event tacts:
- Public accompaniments: The community observes public events that typically accompany the private event (tears, facial expressions) and reinforces the verbal label in their presence
- Collateral responses: The community infers the private event from the individual's other behaviors
- Common conditions: The community knows what conditions typically produce a private event and reinforces the label in those conditions (e.g., "You must be hungry" before lunch)
- Metaphorical extension: The community teaches the individual to describe private events using vocabulary originally learned for public events (e.g., "sharp pain" uses "sharp" metaphorically)
Clinical Implications
Self-Reporting and Assessment
Understanding private events matters clinically because clients report private events (thoughts, feelings, pain, cravings) as part of assessment. A behavior analyst should take these reports seriously as verbal behavior that provides information about the individual's experience, while recognizing that self-reports are verbal behavior under the control of the verbal community's training history and may not perfectly correspond to the actual private events. This is not a reason to dismiss self-reports but rather to interpret them within a behavioral framework.
Acceptance and Commitment Therapy (ACT)
ACT, which has its roots in behavior analysis, directly addresses private events. ACT does not attempt to change the content of private events (thoughts and feelings) but rather aims to change the individual's relationship to those events. From a behavior analytic perspective, ACT targets the derived stimulus relations and rule-governed behavior that give private events their influence over public behavior.
Teaching Emotional Vocabulary
Many ABA programs include teaching clients to identify and label their emotions. Understanding Skinner's analysis of how private event tacts are established helps clinicians design more effective emotional vocabulary programs. Rather than assuming the client "knows" what they feel and just needs the word, the clinician should recognize that the private event tact is being shaped through the same processes as any other tact, with the added challenge of limited access to the controlling stimulus.
BCBA Exam Tips
- Private events are real, physical events that are accessible only to the individual
- Radical behaviorism includes private events; methodological behaviorism excludes them
- Private events are not causes of public behavior; both are caused by environmental variables
- Treating private events as causes is an explanatory fiction
- The verbal community faces a unique challenge in training private event tacts
- Skinner identified four methods by which the verbal community teaches private event labels
This topic connects to the philosophical underpinnings section of the BCBA Task List and is tested both directly and indirectly across multiple content areas. A solid understanding of the radical behaviorist position on private events is foundational for exam success.