The Premack Principle, also known as “Grandma’s Law,” states that a more preferred activity can be used as a reinforcer for a less preferred activity. In other words, if an individual engages in a less preferred behaviorBehavior refers to any activity or action that living o..., they can access a more preferred activity as a reward. This principle is used in behavior modification to increase the likelihood of a desired behavior by following it with something the individual enjoys.
Example
A parent might tell their child, “You can play video games after you finish your homework.” In this case, playing video games (the more preferred activity) is contingent on completing homework (the less preferred activity). The opportunity to engage in the more preferred activity reinforces the completion of the less preferred task.