About Narcissism In General

Those with Narcissism don't try to make, maintain, or repair connections with others unless they're motivated by gain or fear. The concern for another's well-being, for no other reason than the person's well-being, is not in their schedule.

Nor is protecting another, helping another, standing up for another, or supporting another, for any reason other than their own gain or defense.

Many who are afflicted with Narcissism for whatever reason will project their own perceptions and motives onto others, apparently believing that everyone has the same self-serving-based agenda, and that no one is genuinely altruistic or empathetic, and that everyone is always motivated only by gain or fear.
Ironically, without the ability empathize, they are not able to imagine having a different point of view than their own, or that it's possible to have a different point of view than their own and not be "crazy" or "wrong".

The ability to empathize has been linked to specific grey matter areas in the brain, and the presence of "mirror neurons'. So technically, a lack of mirror neurons in a person's brain is neurological, not psychiatric, and should be taken much more seriously by the larger scientific and medical community.
BUT, probably won't be, since the goals of Narcissists within science and medicine are often to occupy positions of authority and control. In other words, a Narcissist who gains the power to divert or shut down research on the neurology of Narcissism would, of course, do just that, to protect themselves.