What Is Behavioral Contrast?
Behavioral contrast is the phenomenon in which a change in the rate of reinforcement in one stimulus condition produces a change in the rate of responding in a second, unchanged condition, and the change moves in the opposite direction. It was first described by Reynolds in 1961 using pigeons responding on multiple schedules, and it has since been observed in many species, including humans.
Two forms are commonly distinguished.
- Negative behavioral contrast: Reinforcement decreases in one component, and response rate increases in the unchanged component.
- Positive behavioral contrast: Reinforcement increases in one component, and response rate decreases in the unchanged component.
The Multiple Schedule Arrangement
Behavioral contrast is studied in multiple schedules, in which two or more schedules of reinforcement alternate and each is signaled by a distinct stimulus. Imagine a pigeon pecking a key under a green light (Component 1) and a red light (Component 2). At first, pecking is reinforced on a variable-interval 60 second schedule in both components. Then, reinforcement is discontinued in the red component (extinction) while the green component remains the same. Responding in the green component often increases above baseline even though the schedule in green did not change. That increase is negative behavioral contrast.
Why Does Contrast Occur?
Researchers have proposed several explanations.
- Relative reinforcement: Behavior is sensitive to the relative rate of reinforcement across conditions. When reinforcement drops in one component, the unchanged component becomes relatively richer, and responding increases there.
- Behavioral allocation and matching: The matching law suggests behavior is allocated in proportion to reinforcement. When the alternative gets less reinforcement, the other receives more behavior.
- Emotional or frustration explanations: Reduction in reinforcement in one component may produce frustration, which energizes responding in the other.
- Pavlovian processes: Stimuli associated with reinforcement can produce approach responses, which add to operant responding.
For the exam, you need to know the definition, the two types, and the typical research arrangement. The specific theoretical account is less likely to be tested in depth.
Contrast in Applied Settings
In applied work, contrast is a reminder that interventions can have effects outside the treatment setting. A few examples show how.
Example 1: school versus home
A student receives a differential reinforcement program with extinction for calling out in the classroom. Calling out decreases at school. At home, where parents have not changed their responses, calling out increases. This is consistent with negative behavioral contrast, in which reduced reinforcement for the behavior in one setting increases it in another.
Example 2: one therapist extinguishes, another does not
A learner's tantrums no longer produce attention during sessions with the primary therapist but continue to produce attention with the afternoon therapist. Tantrums may increase in the afternoon sessions because the afternoon context is now relatively richer in reinforcement.
Example 3: positive contrast
A worker is given a large bonus for sales in one department, and productivity in another department with unchanged incentives declines. This resembles positive contrast, though real workplaces involve many other variables.
Clinical Implications
- Implement consistently across settings and people. If extinction or differential reinforcement is used in one environment, other environments should be included in the plan, or the effects of the plan should be monitored.
- Train all caregivers and staff. Inconsistent responses from different people create the conditions for contrast and spontaneous recovery.
- Collect data across settings. Do not measure behavior in the treatment setting only. Include probes at home, in community settings, and with other people.
- Plan for generalization. Programming common stimuli, training sufficient exemplars, and involving natural communities of reinforcement reduces the risk that unplanned reinforcement elsewhere undermines treatment.
- Increase reinforcement for alternatives. Providing rich reinforcement for appropriate behavior in every setting can reduce the relative value of problem behavior.
- Be cautious with a focus on single contexts. A treatment that appears successful in one setting may have problematic side effects elsewhere.
Contrast vs Related Concepts
- Generalization: Generalization means behavior in one setting spreads to other settings. Contrast is the opposite pattern, with the change moving in the opposite direction.
- Extinction burst: A temporary increase in behavior within the extinction condition itself. Contrast refers to changes in a different condition.
- Resurgence: The reappearance of a previously reinforced behavior when a more recent behavior no longer produces reinforcement. It concerns different response topographies, not different settings.
- Induction: Positive and negative induction refers to changes in related behavior when reinforcement is changed, and is sometimes used for similar phenomena.
Reducing the Risk of Contrast
Use a unified plan
Involve parents, teachers, and other providers, and give each a written plan with clear steps. Practice responses to problem behavior in role-play so everyone responds the same way.
Use differential reinforcement
Rather than simply withholding reinforcement, reinforce alternative behaviors such as functional communication so that the learner still has access to the same outcome in every setting.
Monitor for side effects
Review data across settings weekly. If you see an increase in behavior outside the treatment setting, investigate whether it is a contrast effect and adjust the plan.
Teach discrimination carefully
If different people respond differently, the learner will learn who delivers reinforcement. Discrimination of settings can be useful when intended, such as using a quiet voice in the library and a loud voice on the playground, but not when it undermines treatment of problem behavior.
BCBA Exam Tips
- Remember: contrast means the change moves in the opposite direction in the unchanged condition.
- Negative contrast: reinforcement goes down in one component, responding goes up in the other.
- Positive contrast: reinforcement goes up in one component, responding goes down in the other.
- Know that it is demonstrated with multiple schedules.
- When a scenario shows a behavior increase at home after a school program, think contrast and consistency across settings.
Key Takeaways
Behavioral contrast is an opposite-direction change in responding in an unchanged condition when reinforcement changes in another. It matters because interventions can alter behavior in other settings. Plan treatments across contexts, train everyone involved, and measure behavior outside the primary setting.