Narcissism, even that which isn't severe enough to qualify as a personality disorder, is a mental condition that can hurt people. Those who have this condition tend to act as if the world revolves around them, and they often lash out at those who attempt to give them criticism. One of the methods by which narcissists lash out is by imposing their own silent treatment to cow their naysayers.
Narcissistic personality disorder is defined as a pattern of grandiosity, such as exaggerated claims of talent or importance, a need for admiration, and a lack of empathy for other people. Strictly speaking, a person doesn't have to be severe enough to have narcissistic personality disorder to display a similar need for positive regard, and a callousness towards others.
There are nine symptoms that a psychologist will look for when diagnosing a patient with narcissistic personality disorder. Five of these nine must be met in order for a diagnosis to be made: a grandiose sense of self; living in a fantasy world of perfect beauty, love, power, genius, etc.; thinks of herself as special and only able to be understood by special people; demands excessive amounts of praise or admiration from others; feels entitled to automatic defense, compliance or favorable treatment from others; is exploitative towards others; lacks empathy with others; is envious of others, or feels they are envious of him; has an attitude of haughtiness or arrogance.
The silent treatment the act of completely ignoring a person. It is usually used to express contempt or disapproval. First termed in 1947, the silent treatment is used by a lot of people.
When a person who is a narcissist uses the silent treatment on someone, it can be rather extreme. A narcissist may refuse to speak to or even acknowledge someone for a great length of time, and then demand an apology that is out of proportion to the perceived offense. By demanding this apology, it supports the narcissist's inflated view of herself.
It's theorized that narcissistic personality traits, as well as the use of the silent treatment, are learned behaviors. If a child's emotional needs are not being met, or if boundaries are not given to him, he may develop narcissistic personality traits as a response. Children may also watch others and use the silent treatment as a way to punish others and to get them to comply with the child's wants. While these two things may be learned and displayed separately, often those children who learn narcissistic traits will also use the silent treatment.