Assertiveness is a skill that can be learned. It is a way of communicating and behaving with others, it will help you to have more confidence in yourself. Assertiveness is not a natural behavior we are born with. As we grow up, we learn to adapt our behavior to what happens around us, to the people we meet. If self-confidence is diminished, through irony or violence, when we are adults we will tend to react passively or aggressively in similar situations.