What Is Behavioral Contrast?
Behavioral contrast is a phenomenon observed when reinforcement conditions change in one component of a multiple schedule (or in one setting) and behavior changes in the opposite direction in an unchanged component (or setting). First systematically studied by Reynolds (1961) using pigeons on multiple schedules, behavioral contrast has been demonstrated across species and has important implications for clinical ABA practice.
The concept is straightforward in principle but frequently misunderstood. When a behavior is reinforced in Setting A and Setting B, and then reinforcement is reduced or eliminated in Setting A, you would expect the behavior to decrease in Setting A. Behavioral contrast describes the additional finding that the behavior may increase in Setting B, even though nothing about the reinforcement conditions in Setting B has changed.
Types of Behavioral Contrast
Positive Behavioral Contrast
Positive contrast occurs when reinforcement conditions worsen in one context and behavior increases in the other, unchanged context. For example, if a child's disruptive behavior is reinforced by attention from both Teacher A and Teacher B, and then Teacher A begins ignoring the behavior (extinction), the child's disruptive behavior may increase with Teacher B, who continues to provide attention. The behavior gets "worse" in the unchanged setting.
Positive contrast is the more clinically concerning of the two types because it can undermine treatment that is being implemented inconsistently across settings or caregivers.
Negative Behavioral Contrast
Negative contrast occurs when reinforcement conditions improve in one context and behavior decreases in the other, unchanged context. If reinforcement density increases in Setting A, behavior may decrease in Setting B even though conditions in Setting B have not changed. This type of contrast is less commonly discussed but equally relevant for understanding how behavior allocates across contexts.
Clinical Implications
Inconsistent Treatment Implementation
Behavioral contrast is one of the primary reasons why consistent implementation across all settings and caregivers is so critical. When one caregiver implements extinction for problem behavior but another does not, the untreated setting may see increases in the very behavior the team is trying to reduce. This is not a failure of the intervention itself but a predictable effect of differential reinforcement conditions across contexts.
Consider a common clinical scenario: a BCBA designs a behavior intervention plan that places attention-maintained tantrums on extinction. The school team implements the plan consistently, and tantrums at school decrease. However, the parents report that tantrums at home have actually increased. This could be an example of positive behavioral contrast. The reduction in reinforcement at school has produced an increase in behavior at home, where the reinforcement contingency remains unchanged.
Multi-Setting Intervention Design
Understanding behavioral contrast means that effective treatment planning must consider all settings in which the behavior occurs. A behavior plan that addresses behavior only in the clinic or only at school may inadvertently increase the behavior in other settings through contrast effects. This is why comprehensive treatment planning involves training all caregivers and implementing consistent contingencies across environments whenever possible.
Parent and Teacher Training
Behavioral contrast provides a compelling rationale for caregiver training as a component of every behavior intervention plan. When clinicians explain to caregivers that inconsistent implementation can actually make behavior worse in untreated settings, it builds motivation for consistent followthrough. The science of behavioral contrast gives clinicians an evidence-based framework for explaining why "doing it sometimes" is often worse than not doing it at all.
Mechanisms Behind Behavioral Contrast
Several explanations have been proposed for behavioral contrast:
- Additivity theory: Suggests that emotional responses elicited by changes in reinforcement conditions in one component add to operant responding in the other component
- Behavioral competition: When reinforcement decreases in one component, behaviors that previously competed with the target behavior in that component decrease, allowing the target to increase by default in both components
- Matching Law explanations: Changes in relative reinforcement rates across components produce shifts in response allocation consistent with matching principles
For the BCBA exam, you do not need to evaluate which theory is correct, but you should know that contrast is a well-established empirical finding with multiple theoretical accounts.
Managing Contrast Effects in Practice
Behavior analysts can take several steps to minimize problematic contrast effects:
- Implement interventions across all relevant settings simultaneously: The most effective strategy is to ensure consistent contingencies everywhere the behavior occurs
- Train all caregivers: Every person who interacts regularly with the client should understand and implement the behavior plan
- Monitor behavior across settings: Collect data in all relevant environments, not just the treatment setting, to detect contrast effects early
- Anticipate and prepare caregivers: Warn caregivers that behavior may temporarily increase in untreated settings and provide them with strategies for managing this increase
- Use functional communication training across settings: Ensure that the replacement behavior is honored and reinforced in all environments
BCBA Exam Preparation
Questions about behavioral contrast typically present a scenario where behavior changes unexpectedly in a setting where no intervention changes were made. The correct answer usually involves identifying the contrast effect and recommending consistent implementation across settings. Common distractors may suggest that the behavior has a different function in the unchanged setting or that a new reinforcer is maintaining the behavior. Always consider behavioral contrast when a scenario describes increased behavior in an unchanged setting paired with decreased behavior where intervention was applied.
Key points for the exam:
- Contrast is an interaction between settings or components of a multiple schedule
- Positive contrast means behavior increases where reinforcement did not change
- The primary clinical response is to implement consistent contingencies across all settings
- Reynolds (1961) is the foundational reference for this phenomenon