Say you see your father smoking a cigarette. You know that smoking is bad for his health and you want to convince him to stop. But what is the best way to do that? Most likely, you would warn him that he could die from some sort of disease. But, evidence shows that warnings don’t work too well to convince someone to change their behavior. This is because the most common reactions to threats is either to freeze or flee, not fight. When something scares us, we tend to get rid of the negative feelings by using rationalizations. This creates a boomerang effect and causes us to become more resilient with the behavior we want to change.
Then how do you get motivated to change your behavior? There are three important principles to motivation of behavior change, Social incentives, immediate rewards, and progress monitoring. We are motivated by other people’s opinion, what they are doing, and what you can do better. Rewards also get us fired up to do it, even something as simple as a praise. You should reward yourself now, so you can reach a goal in the future. For example, you should stop smoking now, so you can run more and win your next race. Also, we need to have something that monitors your progress. When we see he progress and positive outcomes of our behaviors, it will motivate you to keep doing it.
So, instead of telling your father that he will die if he does not stop smoking, you should show him pictures of other people stopping that bad habit and promise to treat him to dinner at an expensive restaurant if he stops as well. Also, put up a board and mark down how many days he does not smoke and praise him for not smoking for long periods of time. That will probably convince him to stop more that all of the threats and warnings you were thinking to use.