I've noticed this connection between the disorders of SzPD, NPD, and AsPD.
As a schizoid, I often feel completely misunderstood and isolated, even by those with personality disorders themselves. I've had several volatile (very volatile) relationships with pwBPD, to the point I am repulsed to splitting by anyone who expresses those traits. I find no connection or understanding in hypothetically similar like StPD and AvPD, meanwhile HPD and DPD are antithetical to my experience. (OcPD and PPD just don't apply at all.)
Meanwhile, I've found time and again that those with NPD and AsPD traits are those I can connect with on a basal level, as if our brains are hardwired in the same alternative way.
AsPD has a disregard for social norms - it's in the name. Antisocial. While SzPD tends to be expressed more as Asociality than actively opposing those norms, for me at least, it's due to not wanting to put up with the ramifications of breaking taboos and laws. It would entangle me with others and cause more trouble than it's worth. Even so, I fundamentally do not understand many societal rules, I have no morals, and only follow to not stand out and make trouble for myself. It is also my understanding that often, rule-breaking actions taken by pwAsPD are caused by constant boredom, which is something I struggle with heavily.
NPD is about social hierarchy, classifying people into levels, with a constant need to be at the top of those levels. While I have no sense of self-esteem, i.e. I neither value or devalue myself, I do have a strong sense of certain others being "beneath me". It is my belief that we view others similarly; grayed-out background characters who may be left alone like a fly on the wall, or who may serve a functional purpose, but if they begin to buzz around one's face, demanding attention they do not deserve, upstaging, or simply being annoying, their "value" and thus internal social standing plummets.
For both, there's this term thrown around like a ball; sociopathy.
A sociopath, as I understand it, is someone who is-- well-- apathetic to social norms, to people. Someone who does not feel empathy. Disregards others' feelings, does not express their own, and may have a restricted range of affectation.
This is displayed all the time in TV and movies. At least one character labelled "sociopath" across the Internet and meta-analysis, you can picture, can't you?
Cold, calculated types. Usually unethical, sometimes killers.
I remember when I first heard the term "sociopath" -- it was in a book I read as a child. I asked what it meant. I was told, "someone who has no empathy for other people, and can't connect with them" (paraphrased).
And I can think of exactly three personality disorders that this behavior, this thought process describes.
I don't know. I just think it's interesting.