What is a common example of a primary reinforcer?

A primary reinforcer is a stimulus that is inherently rewarding, satisfying a basic biological need or drive. Food is often considered a classic example of a primary reinforcer because it directly fulfills the fundamental need for nourishment, which is essential for survival. When an organism receives food as a reward for a certain behavior, it naturally reinforces that behavior due to the biological necessity of hunger.

In contrast, money, tokens, and praise are examples of secondary reinforcers. They do not have inherent value but acquire their reinforcing qualities through association with primary reinforcers. For instance, money can be exchanged for food, which is a primary reinforcer, while tokens and praise depend on their association with rewards or approval rather than directly fulfilling a basic drive.