The Behavioral Momentum Theory: Understanding Persistence in Behavior

Imagine a child diligently practicing piano scales. Initially, each note is a struggle, but with consistent practice and positive reinforcement from their teacher, they gradually improve. Soon, they can play the scales flawlessly, almost without thinking. Now, even if the teacher introduces a slight distraction, like a metronome ticking at a different tempo, the child is still likely to continue playing the scales correctly. This persistence, this resistance to disruption, is at the heart of Behavioral Momentum Theory (BMT). BMT, rooted in the principles of operant conditioning, offers a powerful explanation for why some behaviors are so resistant to change, even in the face of obstacles or altered circumstances. It suggests that the history of reinforcement a behavior has received creates a sort of “momentum,” similar to the physical concept, making it harder to stop or alter that behavior.  

This concept of behavioral momentum has significant implications for understanding and influencing behavior in various contexts. From education and therapy to workplace performance and habit formation, BMT provides valuable insights into how to establish and maintain desired behaviors. It explains why well-established habits are so difficult to break and why consistent reinforcement is crucial for building lasting change. By understanding the factors that contribute to behavioral momentum, we can develop more effective strategies for promoting positive behaviors and overcoming unwanted ones. This article will delve into the core principles of BMT, exploring its theoretical underpinnings, practical applications, and the factors that influence its strength, offering a valuable framework for understanding the persistence of behavior.

An Insight into the Dynamics of Behavioral Momentum

The Behavioral Momentum Theory (BMT) is a crucial concept in the field of behavioral psychology, providing profound insights into the persistence and resistance to change of behaviors. Introduced by John A. Nevin in the 1982, the theory draws an analogy between Isaac Newton’s law of momentum of physical objects and the persistence of behavior (Craig, 2023). Nevin hypothesized that all observed changes in behavior are “due to discoverable external variables.” Accordingly, he proposed “to apply the most basic principles of classical mechanics as embodied in Newton’s laws of motion to the study of changes in discriminated operant behavior” (Nevin et al., 1983).

Just as a moving object with greater mass and velocity has higher momentum, behavior that is reinforced more frequently has greater “behavioral momentum,” meaning it is more resistant to disruption or change.

Andrew R. Craig explains:

“Persistence, or resistance to change, is thought to be a fundamental aspect of operant behavior and has received considerable attention in both experimental and applied analyses for several reasons. From a practical standpoint, it is important to understand persistence deeply enough to manipulate it: We may wish to arrange the environment in such a way that we promote persistence of prosocial or adaptive behavior and deter persistence of socially undesirable or maladaptive behavior” (Craig, 2023).

Newton’s Laws of Motion

Newton’s First and Second Laws of Motion, while originating in classical physics, provide a useful analogy for understanding Behavioral Momentum Theory (BMT). Briefly, Newton’s First Law, often called the Law of Inertia, states that an object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. Newton’s Second Law states that the acceleration of an object is directly proportional to the net force acting on the object, is in the same direction as the net force, and is inversely proportional to the mass of the object (F=ma).

First Law of Motion

In the context of BMT, we can draw parallels between physical objects and established behaviors. A behavior with a strong history of reinforcement can be likened to an object in motion. Just as a moving object resists changes to its velocity (speed and direction) unless a force is applied, a consistently reinforced behavior resists disruption. This resistance to change is what BMT terms “behavioral momentum.” The more consistent and frequent the reinforcement history (analogous to greater initial velocity), the greater the behavioral momentum, and the more resistant the behavior is to disruptions such as extinction (withholding reinforcement) or the introduction of competing behaviors. This relates to Newton’s First Law – the behavior tends to persist unless an “unbalanced force” (like extinction) acts upon it.

Second Law of Motion

Newton’s Second Law also has relevance. In physics, a greater force is required to accelerate a more massive object. Similarly, in BMT, a behavior with a stronger reinforcement history (analogous to greater “mass”) requires a greater “force” (e.g., a longer period of extinction, a more potent competing reinforcer) to be altered or extinguished. A behavior that has been consistently reinforced over a long period (high “mass”) will take more effort to change than a behavior that has only been reinforced intermittently or for a short time (low “mass”). Thus, the “force” needed to disrupt a behavior is proportional to its reinforcement history, much like the force needed to accelerate an object is proportional to its mass. This analogy helps illustrate why deeply ingrained habits are so difficult to break; they possess significant behavioral momentum.

Exploring the Analogy

Imagine a large boulder hewn from a cliff that begins rolling down the hillside. The momentum of the boulder pushes it on a path. In order to change this trajectory, another force must strike the boulder, altering the direction. Maladaptive behaviors begin for a variety of reasons. Often the individual mimics the behavior of someone else (social learning theory). Or perhaps, the behaviors is more random. Whatever the initial motivation for a maladaptive behavior is unimportant. However, if the maladaptive behavior is rewarded in some way, it gathers strength and is more likely to be repeated. Basically, the behavior gains momentum.

A behavior with built in rewards has a self-propelling element that is difficult to change. Richard Thaler and Cass Sunstein wrote: “First, never underestimate the power of inertia. Second, that power can be harnessed” (Thaler & Sunstein, 2009). Behavioral momentum is wonderful when the behavior has positive consequences. The healthy behavior and the reward work together to improve the life of the actor.

Nietzsche proposed that the individual person is “found by introspection to be a compact mass of habits and attitudes, a living bundle of motor-tendencies, which are, in the last analysis, biological functions of the organism.” The conscious life of “the individual, with its varied interests and ideals, takes character and direction from these organic tendencies” (DuVall, 1937).

Persistence of Behavior

Healthy habit loops are essential for growth. Paul Dolan wrote that once a habit loop is established, “it becomes difficult to inhibit even when it conflicts with changes in motivation and conscious intentions” (Dolan, 2014). In regards to behavioral momentum, John A. Nevin explains that responding continues at “a steady rate under constant conditions until acted upon by a new variable, just as a body persists in motion until acted upon by an external force.” Moreover, the change “in response rate effected by a given variable depends on the rate of reinforcement, just as the change in motion of a body depends on its mass” (Nevin, 1984).

Nevin introduced his concept of behavioral momentum writing:

“The persistence of behavior in the face of altered conditions suggests that it may be profitable to consider learned behavior as possessing momentum. Moreover, the differential persistence of behavior in the presence of stimuli correlated with different rates of reinforcement suggests that behavioral momentum must depend on a stimulus-specific history of reinforcement” (Nevin et al., 1983).

Basically, a large boulder (mass) rolling down a steep hill (external reinforcement) requires significant counter reinforcement to halt the momentum. The greater the reward of the maladaptive behavior, together with the frequency of the reward, determine the amount of counter reinforcement necessary to extinguish the maladaptive behavior.

See Behavior Reinforcement for more on this topic

Foundations and Conceptual Framework

The BMT posits that the persistence of behavior can be understood through the metaphor of momentum from Newtonian physics. According to Nevin, the resistance of a behavior to change is akin to the resistance of a physical object to changes in its state of motion. In this analogy, the rate of reinforcement corresponds to mass, while the response rate (how often the behavior occurs) corresponds to velocity.

B.F. Skinner wrote that a response “reinforced upon a given occasion is most likely to occur on a very similar occasion, but because of a process called generalization it may appear on occasions sharing only some of the same properties” (Skinner, 1974).

Nevin explains that two aspects of free-operant performance may be distinguished:

• The rate of responding under maintained conditions of reinforcement, and
• The persistence of that response rate when some aspect of those conditions is changed (Nevin, 1984).

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Basically, under the same conditions, behaviors continue. When conditions change (reinforcements) persistence relies on factors of behavioral mass and behavioral velocity.

Reinforcement and Behavioral Mass

In BMT, the concept of “behavioral mass” is used to describe the strength or persistence of a behavior. This mass increases with the rate of reinforcement in a given context. For instance, if a child receives frequent praise for completing homework, the behavior of doing homework becomes more persistent and resistant to disruptions, such as distractions or changes in routine.

Reinforcement, in the context of behaviorism and habit formation, refers to the use of rewards or punishments to strengthen or weaken a particular behavior. It is a key concept in understanding how habits are developed and maintained over time.

Response Rate and Behavioral Velocity

Behavioral velocity, on the other hand, refers to the response rate or how frequently the behavior occurs within a given period. A high response rate indicates a high velocity, suggesting the behavior occurs frequently. The combination of high behavioral mass (due to frequent reinforcement) and high behavioral velocity results in substantial behavioral momentum.

Brian D. Greer and his colleagues explain the role of these two features of Newton’s law in regards to behavior this way:

“Applying this analogy to behavior suggests that when a disruptor (e.g., extinction, satiation, distraction) is applied to ongoing behavior, the rate at which the behavior will decrease is directly related to the magnitude of the disruptor and inversely related to the behavioral equivalent of mass. Said another way, a larger disruptor will decrease responding more quickly than a smaller one; however, a response with more behavioral mass will persist more in the presence of the disruptor than a response with less mass” (Greer et al., 2016).

Success as a Positive Reinforcement

Teresa Amabile and Steven Kramer explain that the motivation of progress was one of the most important findings of their entire study. They explain that: “Making headway on meaningful work brightens inner work life and boosts long-term performance. Real progress triggers positive emotions like satisfaction, gladness, even joy. It leads to a sense of accomplishment and self-worth as well as positive views of the work and, sometimes, the organization. Such thoughts and perceptions (along with those positive emotions) feed the motivation, the deep engagement, that is crucial for ongoing blockbuster performance” (Amabile & Kramer, 2011, p. 68).

The progress loop represents the ultimate power of inertia pushing us forward to higher and higher levels of accomplishment and achievement. Success breeds more success. Success reinforced by a reward creates a powerful loop. The person believes they will succeed and given tasks and expect a reward (often an unconscious process). Albert Bandura explains that efficacy expectations determine “how much effort people will expend and how long they will persist in the face of obstacles and adverse experiences” (Bandura, 1977, p. 194).

Structuring Positive Reinforcement into Goals

Anders Ericsson and Robert wrote that one one of the best bits of advice is to “set things up so that you are constantly seeing concrete signs of improvement, even if it is not always major improvement.” Accordingly, individuals should break your long journey into “a manageable series of goals and focus on them one at a time—perhaps even giving yourself a small reward each time you reach a goal” (Ericsson & Pool, 2016, p. 177).

Positive reinforcement come from success. It is essential to create achievable goals. Mihaly Csikszentmihalyi explains that optimal experiences usually involve “a fine balance between one’s ability to act, and the available opportunities for action.” When challenges exceed coping abilities, the individual first experiences frustration, then worry, and eventually overwhelm. However, when challenges are “too low relative to one’s skills one gets relaxed, then bored” (Csikszentmihalyi, 2008). Too many failures halt behavior momentum. We need the rewards of success, even if those rewards are only received on a Variable-Ratio Schedule.

See the Progress Principle for more on this concept

Empirical Support and Applications of Behavioral Momentum Theory

Numerous studies have validated the principles of BMT across various settings and populations (Pritchard et al., 2014; Trump et al., 2020). These studies have shown that behaviors reinforced at higher rates are more resistant to extinction and disruption, supporting the theory’s predictions.

Applications in Clinical Settings

Nevin and Timothy A. Shahan describe the use of behavior momentum in analyzing, reducing, and eliminating problem behaviors (e.g., aggression, disruption, or self-injury) in a clinical setting. They wrote, “In many cases, the problem behavior has an extensive history and may be extraordinarily resistant to treatment. A standard approach is to conduct a functional analysis to identify reinforcers that maintain problem behavior, such as attention or escape from tasks, and then to withhold reinforcers for problem behavior while functionally equivalent reinforcers are provided for adaptive alternative behavior (e.g., effective communication skills).”

Nevin and Shahan add that if an intervention is truly effective, “problem behavior should decrease and be replaced by adaptive behavior, and these changes should persist in different treatment settings and endure when treatment ends.” Behavioral momentum theory (BMT) is principally concerned with “the resistance to change of operant behavior, and therefore is directly relevant to the reduction or elimination of problem behavior and the establishment of durable adaptive behavior” (Nevin & Shahan, 2011).

BMT has been instrumental in developing interventions for individuals with behavioral disorders. For example, in treating children with autism, therapists use high rates of positive reinforcement to increase desirable behaviors, thereby creating substantial behavioral momentum. This approach helps the desired behaviors persist despite potential disruptions or changes in the environment.

Behavioral Momentum Theory (BMT) is most directly applicable to therapy styles rooted in Applied Behavior Analysis (ABA). However, its principles can also be incorporated into other therapeutic approaches that emphasize behavior change.

Applied Behavior Analysis (ABA)

• Core Application: BMT is a core component of ABA, particularly when working with individuals with developmental disabilities, autism spectrum disorder, or those exhibiting challenging behaviors.  
• High-Probability Request Sequence: A key technique derived from BMT is the “high-probability request sequence” (high-p sequence). This involves presenting a series of easy or preferred tasks (high-probability requests) immediately before a more challenging or less preferred task (low-probability request). The momentum generated by completing the high-p requests increases the likelihood of compliance with the low-p request.  
• Examples:
  1. Asking a child to perform several simple motor tasks (e.g., “touch your nose,” “clap your hands”) before asking them to complete a less preferred task like cleaning up toys.  
  2. In a classroom setting, having students complete several easy math problems before introducing a more complex problem.

See Applied Behavior Analysis for more on this style of therapy

Treatment Relapse

A major concern of applied behavior analysis is treatment relapse. Since ABA relies on behaviorism techniques of reinforcement, there is a great concern for continued extinction of problem behaviors when environments change, such as when treatment ends . The desire is that new behaviors will continue through a generalizing of cues (responding to similar cues in the environment with the new learned behaviors).

Dunkin Pritchard, Marguerite Hoerger, and F. Charles Mace wrote that the field of applied behavior analysis has “treated relapse as a failure to generalize treatment gains over time or across different settings or therapists” (Pritchard et al., 2014).

Cognitive Behavioral Therapy (CBT)

• Indirect Application: While not explicitly named as BMT, CBT incorporates principles that align with it. For example, in exposure therapy for phobias, clients gradually expose themselves to feared situations, starting with less anxiety-provoking scenarios and progressing to more challenging ones. This gradual exposure builds a sense of mastery and reduces anxiety, which can be seen as a form of behavioral momentum.  
• Behavioral Activation: A component of CBT used to treat depression, behavioral activation involves scheduling enjoyable activities to increase engagement and motivation. This can create positive momentum, making it easier for individuals to engage in other beneficial behaviors.  

Other Therapy Styles

• Any therapy with a behavioral component: Any therapeutic approach that involves setting goals, breaking down tasks into smaller steps, and providing positive reinforcement can benefit from incorporating BMT principles. This could include therapies focused on habit change, addiction recovery, or skill development.

Key Takeaways

• BMT is most directly and extensively used within ABA.  
• Other therapies, particularly CBT, utilize principles that align with BMT, even if they don’t explicitly use the term.
• The core idea of building momentum through prior success can be a valuable tool in any therapy that aims to promote behavior change.

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By understanding and applying the principles of BMT, therapists can create more effective interventions that promote positive behavior change and increase client success.

See Clinical Psychology for more on this topic

Educational Applications

In educational settings, teachers can apply BMT principles to increase student engagement and persistence in academic tasks. By frequently reinforcing positive behaviors, such as participation or homework completion, teachers can enhance the students’ behavioral momentum, making these behaviors more resistant to distractions or negative influences.

Organizational Behavior

Organizations also leverage BMT to improve employee performance and job satisfaction. By consistently reinforcing desirable behaviors, such as meeting deadlines or collaborating effectively, employers can foster a work environment where these behaviors become ingrained and persist even under challenging circumstances.

See Organizational Psychology for more on this topic

Challenges and Criticisms

Despite its wide acceptance and application, BMT has faced several criticisms. Some researchers argue that the theory oversimplifies complex human behaviors by likening them to physical objects. They contend that factors such as cognitive processes, emotional states, and social contexts play a critical role in behavior persistence and are not adequately addressed by the model.

Moreover, BMT primarily focuses on behavior maintained by positive reinforcement, with less emphasis on behaviors influenced by negative reinforcement or punishment. Critics suggest that a comprehensive understanding of behavioral persistence requires considering these aspects as well.

Future Directions and Research

The future of BMT research lies in addressing its limitations and expanding its applications. Incorporating cognitive and emotional factors into the theory could provide a more holistic understanding of behavioral persistence. Additionally, exploring the effects of negative reinforcement and punishment on behavioral momentum could offer valuable insights.

Integration with Other Theories

Integrating BMT with other behavioral and cognitive theories may enhance its explanatory power. For instance, combining BMT with the principles of operant conditioning or the cognitive-behavioral framework could offer a more nuanced perspective on behavior change and persistence.

See Integrative Therapy for more on this topic

Resurgence

A significant challenge in therapies utilizing behavior momentum theory techniques is resurgence. Research has encountered a problem of a problem behavior returning if the replacement behavior ceases. Since problem behavior extinction is often achieved through replacing a problem behavior with an adaptive alternative behavior this can be of great concern. However, limited research and literature is available on addressing this problem.

Shahan and May M. Sweeny wrote although “resurgence is increasingly recognized as an important behavioral phenomenon, there has been little attempt to systematize the existing literature or to provide a formal account of the processes governing resurgence” (Shahan & Sweeny, 2011). Research must continue to research this challenge and therapist must consider effective responses to minimize client’s risk of relapse.

Technological Advancements

Advancements in technology, such as neuroimaging and artificial intelligence, present exciting opportunities for BMT research. These tools can help researchers observe the neural mechanisms underlying behavioral momentum and develop more effective interventions based on these insights.

Associated Concepts

• Life Trajectories: These refer to the course and pattern of an individual’s life experiences, including their development, relationships, and achievements over time. Psychologists study life trajectories to understand how different factors such as genetics, environment, and personal choices influence the direction and outcomes of a person’s life.
• Behavioral Neuroscience: This field, also known as biological psychology, biopsychology, or psychobiology, is the study of the biological bases of behavior and mental processes. It explores how the brain, nervous system, hormones, and genes influence our thoughts, feelings, and actions.
• Resisting Change: This concept refers to the natural inclination of individuals or groups to oppose alterations in their environment, behavior, thoughts, or beliefs. This concept is often associated with the fear of the unknown, the comfort of familiarity, and the potential loss of control.
• Ivan Pavlov’s Classical Conditioning Experiments: These experiments refer to a series of experiments conducted by Ivan Pavlov in the late 19th century. He discovered he could condition a dog to salivate at the sound of a bell. Pavlov’s research is a prominent element in the upcoming behaviorist movement occurring during that at time.
• Drive Reduction Theory (Clark Hull): Hull suggested that behavior is an attempt to reduce drives, which are internal states of tension or arousal. When an action satisfies a drive, the satisfaction reinforces the behavior.
• Feedback Loops: These processes are crucial for change in psychology, influencing behavior, emotions, and thought patterns. These self-regulating processes can be positive or negative, impacting learning, decision-making, and relationships.
• Life Scripts: This concept rooted in Transactional Analysis, posits that individuals unconsciously develop life plans during childhood, influenced by parental messages and early life experiences. These scripts, often self-fulfilling prophecies, shape our beliefs, behaviors, and relationships throughout life.

A Few Words by Psychology Fanatic

The Behavioral Momentum Theory has significantly advanced our understanding of behavior persistence, providing a robust framework for explaining why certain behaviors endure despite disruptions. While it has its limitations, the theory’s applications in clinical, educational, and organizational settings underscore its practical value. As research continues to evolve, integrating cognitive, emotional, and technological perspectives will likely enhance the theory’s explanatory power, offering deeper insights into the dynamics of behavioral persistence.

In sum, BMT remains a vital tool for psychologists, educators, and organizational leaders, guiding the development of interventions and strategies that promote desirable behaviors and mitigate undesired ones. By continuing to explore and refine this theory, we can better understand and influence the behaviors that shape our lives and societies.

Last Update: September 28, 2025