Controlling Behavior

First brief explanation about behavior according to Wikipedia: Behavior or behaviour is the range of actions and mannerisms made by individuals, organisms, systems, or artificial entities in conjunction with themselves or their environment, which includes the other systems or organisms around as well as the (inanimate) physical environment. It is the response of the system or organism to various stimuli or inputs, whether internal or external, conscious or subconscious, overt or covert, and voluntary or involuntary.

Controlling behavior is not easy task or thing to do.

First, why we need to control behavior; for what?

Not everyone or creature can behave same way.

What are the basic rules are there to controlling behavior and how they can be applied?