Borderlines are not anti-social. Unlike sociopaths, Borderlines have a tremendous desire to be accepted by others. They even go so far as to offer themselves up to others in exchange for their idea of safety and becoming "whole." Since the disorder is a developmental arrest, it is thought-based, and the attachment insecurities float to the surface where they swing wildly back and forth between clinging and hating, good and bad and they use others to feel better about themselves. Borderlines cannot self soothe.
The anti-social personality (Aspd) sociopath on the other hand, purposefully uses others as disposable commodities because he refuses to follow a moral guide, and he does not care what you think about that. Borderlines do care, very much.
The sociopath may use every opportunity to screw up in order to elicit pity from others- he knows this attracts rescuers and he uses them. He also knows he is doing wrong (he is not childlike but rather cunning) and understands consequences- which has him jumping ahead with a story for *why he deserves your pity* and is unaccountable for consequences when he gets caught.
The Borderline isn't as self-assured. Borderlines do not charm- they MIRROR. Because of this, they are often confused when mirroring is questioned during the attachment. If the partner demands that the real self emerge, the Borderline can become emotionally distraught. Since Borderlines have deficient egos, they have a tendency to feel persecuted for their failure to “be.” They have been scapegoated for most of their lives in this manner and they know only how to scapegoat back in retaliation. Borderlines are emotionally immature.
As the Borderline frantically back pedals and projects persecution to get out of the failed mirroring, the partner gets pulled into an understanding driven role. It is at that time that Borderlines show you how they were treated as children, with avoidant, passive aggressive behavior that includes silent treatment and sulking- as though they were professional victims. They do not understand conflict resolution because Borderline personality disorder is a disorder that is fusional and symbiotic. If the attachment is bad, the Borderline feels bad. (Sociopaths could care less.)
If Borderlines mirror the right people, such as Narcissists, the counter-transference can be life affirming to both parties in the beginning, but to the Borderline it triggers a bondage persecution because one self is grand and the other is deficient. The persecution complex behavior is not done in order to fool people with bad behavior like a Sociopath- it's done to prove themselves correct about their ideas of reference concerning their earliest failures to “be.” This failure to "be" erupts into emotional dysregulation that illustrates their insecurities due to what they perceive to be a failed attachment. These are the distorted perceptions of the borderline.
The partner of the Borderline often misunderstands the emotional dysregulation (which makes it worse) and casts the Borderline into an anti-social, morally corrupt role- as this is the easiest and simplest solution to split an emotionally dysregulated human being (who has gone from mirroring good to projecting evil) to protect their own ego.
In the mind of the partner, and to protect their ego, the Borderline is evil- and has done horrible things on purpose- because deep down, they are bad people- flawed and morally corrupt. When we judge Borderline behavior based on our own concept of good- we eliminate the good- and this defense mechanism allows us to remain safe and make the decision of guilt on another party. This is a primitive defense mechanism known as "splitting."
In order to have more realistic interpretations in the conclusion of the relationship- you will be presented (in hindsight) with what was mirrored- and then realize that this part of you was important enough to be recognized by a person who survived their childhood by finding their parent's Achilles heel and using the knowledge of it to manipulate. This gave them what they needed for survival. They did this to you in order to attach to you and survive.
Consequently, your understanding should be that they grew up to be masters of mirroring, *keenly* That means that they needed to feel the fusional quality that this type of attachment requires to feel whole. It however, is not realistically possible to live in this way.
You will also never be someone that can be trusted in the aftermath of the break-up- because your withdrawal has proven exactly what they fear. It is a defectiveness schema of their part time selves that swing wildly back and forth on a pendulum between good and bad, reward and withdraw. You have just proven to them what they secretly fear all along, that they are bad.
Apart from you- they now must seek out a new rewarding self that is found in a new persona to re-create the insecure attachment bond all over again. Since this disorder is repetitious, it is a re-living of their distorted perceptions concerning their past inability to form their own self apart and whole from their parent. In short, it is the failure to grow up and mature as a self sufficient human being without blaming others.
Borderline is different from Aspd. It is a repetition compulsion to acknowledge the deprived, defective part-time self and make it whole with the addition of a new rewarding object.
If you are dealing with a Sociopath, there are several forums that can give great advice.
