What can reinforce a behavior effectively when given after that behavior occurs?

A reinforcer is a stimulus that increases the likelihood of a behavior being repeated when it is presented immediately after the behavior occurs. This concept is rooted in operant conditioning, where behaviors are influenced by their consequences. When a desirable outcome or reward follows a specific behavior, it reinforces that behavior, making it more likely to happen again in the future.

In this context, a reinforcer can take various forms—such as praise, rewards, or positive reinforcement—depending on what effectively motivates the individual. The timing of the reinforcer is crucial; it must follow the behavior closely to establish a clear connection between the action and the outcome. This immediate reinforcement is what strengthens the association in the individual's mind.

While consequences can influence behavior, they encompass both positive and negative outcomes, making them broader than the specific role of a reinforcer. Feedback, in some instances, can provide valuable information about performance but does not always serve as a reinforcement in the traditional operant conditioning sense. Punishment tends to reduce undesirable behaviors rather than reinforce desired ones. This makes the reinforcer the most fitting choice for effectively increasing the likelihood of a behavior when presented after it occurs.