When Brice was first training his dog to do a "high five," he gave it a treat for any behavior, such as lifting its paw, that approximated the desired end-goal behavior of a "high five." This process is called .

The answer is shaping.

Explanation:

This concept explains that a target behaviour can be achieved by succesive approximations. This is, similar actions will be reinforced until they reach the target.

For example, if a researcher is trying to teach a rat to push a lever, he will reward similar behaviours first (standing near the lever, touching the lever...). The reinforcement then will be stopped, and the subject will likely attempt another similar behaviour. Eventually, the rat will push the lever and be rewarded for it.