Assertiveness is the ability to express your feelings, opinions, beliefs and needs directly

“Assertiveness is the ability to express your feelings, opinions, beliefs and needs directly, openly and honestly, while not violating the personal rights of others.”

(Holland and Ward 1990) Corollary to which, being assertive entails knowing its limit because the right of a person ends where the right of another person begins.  Being assertive is an expression and protection of one’s right up to such an extent where one protects and respects the rights of others.

“There’s a kind of integrity that goes along with assertiveness — meaning what you say, when you say it, in the way that you say it.” (Davidson, J. 1997).  Thus, it is ultimately aimed at generation a resolution to problems that is amenable and beneficial to all, essential to maintain fairness and mutuality, which are the basic tenets of any form of human relationships.
Rights
In legal parlance, a right is the legal entitlement to do or avoid doing something which is sanctioned by law or the provisions of a contract. However, everyone has rights that are inherently conferred to us by virtue of being humans, which is called human rights. (Gewirth, 1998) Human rights are universal, every person is entitled to it; equal, every person has the same rights; and entail a correlative duty, the bearer of which under international law is the state or the government to which a person had pledged allegiance to.
(Clapham, 1993) Perhaps the most basic of these human rights which Immanuel Kant himself declared is freedom –nobody owns one’s life except oneself.  From which the following rights can be derived: the right to decide for oneself in terms of behavior, idea and emotion; the right to change the same, the right to be independent in the conduct of one’s life, to join and not to join, to act or not to act or the right to have a choice.
However, in the exercise of these rights, people are prone to commit mistakes.   The right to commit mistakes therefore is in essence part of a person’s right to make decisions and to have choices.  In as much as a person has the right to commit mistakes, he/ she also has the responsibility for the consequences of his/ her choices and decisions.
Assertiveness is the balance between two extreme behaviors: passiveness and aggressiveness.  Passiveness or being non assertive is the renunciation of one’s rights which involves turning down one’s opinions, allowing others to decide for one’s own fate, or not exercising one’s right because of guilt or anger.
Aggressiveness or being too assertive is the abusive exercise of one’s rights which involves intimidating other people, coercing or manipulating others (lying) thereby not allowing them to decide for themselves or, exercising one’s right to an extent of exploiting other people’s rights.  (Lloyd, 2001)
In other words, “people have a fundamental right as human beings to express themselves so long as doing so will not trample on the rights of others.” (Davidson, J. 1997) Such assertion becomes am aggression
Barriers to Assertiveness
A big barrier to assertiveness is the over watchfulness or worrisome of people to be misinterpreted as being aggressive and offensive.  It may anger others or hurt their feelings and consequently engender a feeling of hatred, a perception of arrogance or selfishness or even stupidity against the assertive person.
These misled conclusions are basically drawn from misconceptions about assertiveness which involved legitimate rights, a sense of concern towards others and a sense of responsibility for the consequences of one’ s decisions. (Paterson and Paterson, 2000)