In the past, the terms "self-control" and "willpower" were often used together to describe a person. If someone lacked self-control meant they just did not have enough willpower. If someone was well-behaved and wise, they had a lot of willpower. However, according to Skinner self-control and willpower were not one and the same.
Skinner believed self-control was an issue of conflicting outcomes and managing conflicts like these has two types of responses: controlling response and controlled response, by doing one it affects the other. Types of controlling responses are physical restraint, depriving and satiating, doing something else, and self-reinforcement and self-punishment. Physical restraint is when you physically manipulate the environment to prevent problematic behavior from happening. Depriving and satiating are used as a tactic to stop a behavior. For example, you eat a meal before grocery shopping so you are not hungry while shopping and buy unnecessary foods. Doing something else is used to distract yourself from not the behavior you are trying to avoid. For example, chewing gum instead of smoking a cigarette. Self-reinforcement is simply reinforcing your own behavior even though Skinner belies this extremely difficult. Skinner says punishing yourself can be very difficult because at some point most people just stop doing the punishment. A video linked below of Skinner talking about Self Management of Behavior.
Powell R. A., Honey P. L., & Symbaluk D. G. (2016). Introduction to Learning and Behavior. [VitalSource Bookshelf]. Retrieved from https://bookshelf.vitalsource.com/#/books/9781305887480/