Atypical, thanks you clearly have a good understanding of these PDs.
I have read much about narcissism.
'The People Of The Lie' and a 'Road Less Traveled' by Scott Peck explains the evil that is pathological narcissism, and the damage it can do.
I have observed my Narc parents, my powerful controlling narc sister and a previous partner who over a year I slowly realized was a high functioning psychopath. (Oh yes, I know how to pick um)
All these people I have no doubt were born like it.

There has been some research that indicates psychopaths lack neuro receptors for Oxytocin the 'love drug' hence their lack of empathy. This makes sense to me.

StbGuy
I don't even understand how they can say narcissists don't feel empathy for others. How do narcissists then identify those feelings so easily in order to manipulate the other individual? How do they know so easily when it's occurring in others?
I think its like---------------a tiger, a tiger understands its prey totally. It watches sooo carefully, every movement, every twitch, reads the body language, calculates how and when to strike. Its does not need to feel empathy, it just needs to study its prey.