Answer:
Primary
Explanation:
In psychology and operant conditioning, the term Primary reinforcer refers to the biological reinforcers that determine our behavior. In other words, they are part of our nature and reinforce behaviors in a natural way without a process of learning from us, since they are, by themselves, satisfying a biological need. Therefore, they have innate reinforcing qualities. Examples of these reinforcers would be: food, sex, water, sleep.
Therefore, in operant conditioning, a primary reinforcer is innately reinforcing, often by satisfying a biological need.