In operant conditioning, what is the term for a stimulus that increases the likelihood of a behavior?

In operant conditioning, reinforcement is the term used to describe a stimulus that increases the likelihood of a behavior occurring in the future. This reinforcement can be positive or negative: positive reinforcement involves presenting a rewarding stimulus following a desired behavior, which increases the chance that the behavior will be repeated. For example, giving a child praise or a treat for completing their homework serves as positive reinforcement.

Negative reinforcement involves the removal of an unpleasant stimulus when a desired behavior occurs, thereby also increasing the likelihood of that behavior. For instance, taking pain medication to relieve headache pain reinforces the behavior of taking medication when experiencing discomfort.

The other terms mentioned in the options do not describe a stimulus that promotes behavior. Stimulus discrimination refers to the ability to differentiate between similar stimuli and respond differently to them. A conditioned stimulus is linked to a conditioned response in classical conditioning, not specifically related to operant conditioning behavior reinforcement. Extinction refers to the diminished response to a behavior when it is no longer reinforced. Therefore, reinforcement is the core concept that describes how stimuli can encourage and strengthen behaviors through either the addition of rewarding stimuli or the removal of aversive stimuli.