Some behavior falls apart the moment anything changes. Other behavior keeps going through a new room, a new staff member, a missed snack, or even extinction. Behavioral momentum is a way to describe and predict that difference.
Why it matters
You want skills you teach to hold up when real life gets messy: a substitute teacher, a noisy waiting room, a tired afternoon. You also want problem behavior to stay low when a treatment is applied imperfectly. Momentum research shows that how often a behavior happens and how hard it is to disrupt are two different things, and that some well-meant treatment choices can make problem behavior more persistent.
Practice items on this task ask you to define resistance to change, recognize a high-probability request sequence, or predict which of two behaviors will hold up better when a disruptor appears.
Key ideas
- A physics metaphor. In physics, momentum depends on velocity and mass. In behavioral momentum theory (developed by John Nevin and colleagues), response rate plays the role of velocity and resistance to change plays the role of mass. A heavy object keeps moving when pushed; a "heavy" behavior keeps occurring when disrupted.
- Strength is measured by persistence, not by rate. To see how strong a behavior is, introduce a disruptor and see how much responding continues compared with baseline. Common disruptors include extinction, satiation (free access to the reinforcer before a session), distraction, and a competing source of reinforcement.
- Rate and persistence have different sources. Response rate is governed mainly by the response-reinforcer relation: the contingency between a specific response and its consequence. Resistance to change is governed mainly by the stimulus-reinforcer relation: the overall rate (and magnitude) of reinforcement obtained in that stimulus context, whether or not it depends on the target response.
- More reinforcement in a context means more persistence there. Behavior in a context with richer reinforcement tends to resist disruption more than behavior in a leaner context.
- The treatment paradox. Adding noncontingent or alternative reinforcement (for example, DRA) in the same context where problem behavior was reinforced can lower its rate while making it more resistant to change. If the treatment later lapses, the problem behavior may come back strongly. Researchers have studied ways to reduce this risk, such as teaching the alternative response in a different context before bringing it into the problem context.
- The applied cousin: the high-p sequence. Before a request the learner usually does not follow (low-p), you present several quick requests the learner reliably follows (high-p) and reinforce each one. Compliance with the low-p request often improves. The procedure is named for the momentum metaphor; researchers still discuss whether it works by exactly the same process.
Definitions
- Behavioral momentum: a metaphor and theory describing the tendency of reinforced behavior to persist when conditions change, with greater persistence in contexts that have provided richer reinforcement.
- Resistance to change: how much responding is maintained, relative to baseline, when a disruptor is introduced. It is the main measure of response strength in momentum theory.
- Disruptor: any change in conditions that tends to reduce responding, such as extinction, satiation, or distraction.
- High-probability request sequence (high-p sequence): an antecedent procedure in which 3 to 5 easy requests with a strong compliance history are delivered in quick succession and reinforced, followed right away by a low-probability request.
Examples from a session
Momentum in practice
- High-p at home. Jalen, age 6, rarely puts his blocks away. His RBT says, "Give me five," "Touch your nose," "Show me a big smile," praising each one quickly, then within a few seconds says, "Blocks in the bin, please." Jalen cleans up much more often than when the cleanup request comes out of the blue.
- Persistence across contexts. In a clinic, Rosa, age 10, sorts laundry in two rooms. Room A provides reinforcement about every 30 seconds on average; Room B, about every 2 minutes. When a loud video starts in the hallway, sorting holds up better in Room A, where more reinforcement has been delivered.
- The paradox at school. A team adds frequent attention for hand-raising in the same classroom where Theo, a teenager, used to get attention for calling out. Calling out drops. When a new aide stops delivering the attention, calling out comes back strongly, just as momentum theory predicts.
When you plan a high-p sequence, pick requests the learner currently follows nearly every time, deliver them briskly, reinforce each one, and present the low-p request immediately afterward.
Common mistakes / exam traps
- Confusing the high-p sequence with the Premack principle. In the high-p sequence, easy requests come before the hard one. The Premack principle makes access to a high-probability activity contingent on completing a low-probability one.
- Leaving a long gap. A long pause between the last high-p request and the low-p request weakens the effect.
- Mixing up two persistence findings. Intermittent schedules tend to produce more responding in extinction than continuous reinforcement. That is a separate finding; momentum focuses on reinforcement rate within a stimulus context.
Exam trap
Response rate vs. resistance to change. Two behaviors can occur at the same rate yet differ in how well they survive a disruptor. If an item asks which behavior is "stronger," look at responding under the disruptor relative to baseline, not how fast it occurs. Then ask which context has delivered more reinforcement.
Exam trap
Response-reinforcer vs. stimulus-reinforcer relation. The response-reinforcer contingency mainly sets rate; the total reinforcement in the context, contingent or not, mainly sets persistence. So DRA or NCR added in the same context can lower problem behavior's rate while making it more persistent if treatment lapses. Do not assume alternative reinforcement always protects against relapse.
Quick check
Amara, a BCBA, wants to compare how strong two of a client's newly taught skills are, using behavioral momentum logic. Which measurement plan fits best?
Related topics
- Simple schedules of reinforcement: FR, VR, FI, and VI (B.9)
- Compound schedules: concurrent, multiple, mixed, and chained (B.10)
- Operant vs. respondent extinction, as procedure and as process (B.11)
- Recognizing response maintenance (B.15)
- The matching law and how responding is allocated (B.23)
- Differential reinforcement (DRA, DRO, DRL, DRH) with and without extinction (G.2)