What are stimuli that act as reinforcers without prior learning called?

Stimuli that act as reinforcers without prior learning are referred to as unconditioned reinforcers. These stimuli are inherently valuable and do not require any previous experience or conditioning to be effective. For example, food, water, and sleep function as unconditioned reinforcers because they satisfy basic biological needs essential for survival.

In contrast, conditioned reinforcers require learning to gain their reinforcing properties; for instance, money becomes a reinforcer through its association with acquiring food or other primary needs. Aversive stimuli typically refer to unpleasant stimuli that can lead to behavior change due to their unpleasant nature, while neutral stimuli do not affect behavior and do not reinforce or punish actions. The concept of unconditioned reinforcers is foundational in understanding behavior analysis and the principles of reinforcement.