Assertiveness is the process of expressing thoughts and feelings while asking for what one wants in an appropriate way. You need to present your message without falling into stereotypical “too pushy” (aggressive) or “not tough enough” (nonassertive–passive) traps.
Passive or nonassertive behavior comes primarily through the obedient child or supportive parent ego state. Passive behavior is an avoidance of behavior or an accommodation of the other party's wishes without standing up for one's own rights. Passive people tend to deny the importance of things. When people know someone is passive, they tend to take advantage of the person.
Aggressive behavior comes primarily through the adapted child and the critical parent ego states, often through anger. Aggressive people are demanding, tough, rude, and pushy. They are very competitive, hate to lose to the point of cheating, and tend to violate the rights of others to get what they want. When faced with aggressive behavior, the other party often retaliates with aggressive behavior (fights back) or withdraws and gives in (takes flight).
Passive–aggressive behavior is displayed in different ways. The person uses both types of behavior sporadically. The person may be passive one day or moment and aggressive the next. The person uses passive behavior during the situation, then shortly after uses aggressive behavior. Passive aggressive behavior can confuse others and lead to harmful human relations.
Being assertive can create a win–win situation. Assertive behavior is different from aggressive behavior, and the terms are not interchangeable.