Iznahs wrote:
What is the difference?
The difference is that a "disorder" is social, a personality structure is individual.
It's the same difference as between being a criminal or having bad habits.
While people would say all criminals have bad habits, not all people that have bad habits are criminals.
So you could have those personality structures and do fine socially and in fact, most people do to some degree or other. They are just common ways to deal with things and self-identify. In other words, those personality structures are not inherently bad, it's a best something to watch for, but never will be able to achieve entirely, because it's how people roll.
So like when you say "quiet" borderline, it kind of takes out the edge of what borderline is and why it is diagnosed as such in the first place. Just the same with plenty of others, like covert narcissism, or secret schizoid. See, in all those cases, nobody can spot them because they are invisible, so they loose automatically their "disorder" part. It's basically only good at self identification, but without the back and forth with others, it could just be delusional.
It's a bit like the psychopath that never gets caught and overall acts like most people. It's only that they have "bad thoughts". But nobody really cares, it's not what people have problem with. They have problem with people that break laws or create disturbances without any reasons. So we try to explain said behavior and people come up with personality structures to explain. Usually wild guesses and overgeneralized, but that "experts" consider more or less accurate in general or a valid part explanation. When people identify with those structures directly by self-diagnosis, it looses the "disorder" part because the causality is not solid enough.
Just think about causality in general. I want to explain why someone stops in the middle of the road while driving. I could come up with plenty, like there was a red light, which is a strong causal link, but also I could come up with others, like prudent drivers, or just the driving itself, or the type of cars and so on. You can find plenty of correlations like that that are not strictly causal. They might or might not. Personality structures fall into the second category and the more you try and expand the original definition, the less it is causal. Like stopping in the middle of the road is pretty close to the definition of a red light whose goal is to do just that. So it makes sense that a red light would cause the behavior. So those personality disorders in the DSM are pretty much of that nature. The few "traits" are so close to actual behavior and sometimes are plainly behavior, that it is true by definition if you assume the behavior is bad, so there is no real explanatory power to them.
But that is not what the average person wants. They are not happy for you to just say the car is stopped because there is a red light, it's too obvious and they know that already. What they want is a hidden meaning to the stopping, something you could tell before you are aware of the red light. So it's how and why they come up with those personality structures. The structure might be true, people might think in that way, but the overall morality and link to action is lost, so not very useful.