What process increases the likelihood or frequency of a specific behavior?

Reinforcement is the process that increases the likelihood or frequency of a specific behavior. It can occur through various forms, such as positive reinforcement, where a desirable stimulus is presented following a behavior, or negative reinforcement, where an aversive stimulus is removed in response to a behavior. This mechanism strengthens the connection between the behavior and its consequences, making it more likely to be repeated in the future.

In contrast, punishment involves introducing an unpleasant consequence following a behavior, which is intended to decrease the frequency of that behavior. Conditioning refers to the broader process of learning associations between stimuli and responses, but it does not specifically focus on increasing behavior. Extinction, on the other hand, involves the reduction of a behavior when it is no longer reinforced, leading to a decrease in frequency. Therefore, reinforcement specifically addresses the enhancement of behavior frequency, which is why it is the correct choice.