Let's say you're a little kid and you really like to eat candy all the time, but your parents tell you that you can only have it once in a while. How do you change your behavior? Behavioral change theories are ideas and explanations for how people can change their habits and behaviors.
One popular theory is called the "ABC model." It stands for Antecedent (something that happens before a behavior), Behavior (the action you take), Consequence (what happens after the behavior). For example, every time you see candy, you start to feel hungry for it (antecedent). You take the candy and eat it (behavior). You get a sugar rush (consequence).
Another theory is called the "Stages of Change Model." It explains how people go through different stages when trying to change behavior. The stages are pre-contemplation (not even thinking about change), contemplation (thinking about change), preparation (getting ready to change), action (doing something to change), maintenance (continuing the change), and relapse (going back to old behavior).
A third theory is called the "Theory of Planned Behavior." It explains that people's behavior is influenced by their attitudes, beliefs, and intentions. If you think something is important, you're more likely to do it. Let's say you believe it's important to brush your teeth every day (attitude). You know it will keep your teeth healthy (belief). You have a plan to brush your teeth twice a day (intention).
All of these theories can help you make changes in your habits and behaviors. It's important to understand what's motivating your behavior and what you can do to change it.