They cannot tolerate the idea that someone might be their equal
Unfortunately for Narcissistic individuals, there are other people around who also feel as if they too deserve attention. The Narcissist’s response depends almost entirely on where the other person is in the Status Hierarchy. If the person is someone the Narcissistic individual looks up to as having much higher status, no fight will occur. However, if the other person is about at the same level, then the Narcissistic individual will fight ruthlessly to prove that the other person is actually far below them. They literally cannot tolerate the idea that someone might be their equal. Anyone who is seen as competition will be fought with until either the Narcissist feels as if he or she is clearly the winner, or has lost badly and then needs to repair his or her self-esteem. Narcissistic individuals have only two basic tools that they use for self-esteem repair.