Examples of operant conditioning often deal with rodents pressing levers. However, in nature, rodents normally don’t ever encounter levers. How exactly are we able to train rodents to participate in lever pressing? Similar to learning a complicated dance, an animal cannot learn how to perform a complex behavior all at once. Instead, learning complex behaviors is best served by breaking down the behavior into smaller pieces. Shaping is the process of guiding an organism to perform a complex behavior through many successive trials by reinforcing small segments of the behavior.

Let’s say you want to train a rodent to press a lever, so you place it into a container with a lever in one part of the cage. At first, the rodent will explore the cage randomly. The first step in training it to press a lever may be to reward it whenever the rodent turns to face the lever. After multiple applications of this positive stimulus, the frequency with which they decide to perform this behavior will likely increase. Next, we would halt rewards for performing this segment of the behavior. Instead, we will now reward the rodent whenever he faces the lever and moves toward the lever, until the rodent increases the frequency with which they perform this behavior. Lastly, we will reward the rodent only when it faces the lever, moves toward the lever, and touches the lever. When this behavior is reinforced, we will only reward the rodent when it faces the lever, approaches the lever, touches it, and physically moves the lever. Therefore, over successive trials, we will have taught the rodent segments of the complex behavior, which are then combined into the more complex behavior we actually desired.