The Narcissist NEVER gives up one of their screaming fits or arguments until they get exactly what they want or destroying you in the process. If you engage the Narcissist he/she will pull you down to their level. Keep engaging with them in an argument and he/she will take it to another destructive level and another and finally to a level lower then you care to stoop so you just give in and stop.
It is futile to go on anymore so this behavior becomes your normal when dealing with a Narcissist. It is sadistic conditioning pure and simple and facilitates the Narcissist's delusions of power and control and abuses YOU!"............. Read entire article @ - After Narcisstic Abuse