What is the best definition of differential reinforcement?

• A. Providing greater reinforcement for better approximations of a target behavior, and placing other behaviors on extinction or on a less desirable reinforcement schedule.
• B. A stimulus that signals the availability of a reinforcer.
• C. A stimulus that, when presented following a behavior, causes an overall increase in that behavior over time.
• D. A stimulus that, when presented following a behavior, causes an overall decrease in that behavior over time.

Answer: (A)

Differential reinforcement means reinforcing some occurrences of a behavior more than others, specifically giving more reinforcement for closer or better approximations to the target behavior while withholding reinforcement or using a less favorable schedule for all other behaviors. This shapes the desired behavior by rewarding the best attempts and letting competing or unwanted behaviors wane through extinction or minimal reinforcement.

So this best definition captures the core idea: you reward the better versions of the target behavior and reduce reinforcement for other behaviors, guiding the learner toward the desired response. For contrast, a signal that merely indicates reinforcer availability isn’t differential reinforcement, and simply increasing a behavior with reinforcement isn’t about differentiating between behaviors. The idea of a stimulus that decreases behavior describes punishment or extinction directly, not differential reinforcement.