Above, in this 7 minute video, Jordan Peterson, a clinical psychologist and Professor, addresses BPD.
Midway through the video he pauses as he visualizes what he is about to say, then states how BPD reflects a disassociation between IQ and conscientiousness, in this I feel he using the word "conscientiousness" to refer basically to the emotional body. Later he brings this forward as he refers to the temper tantrum capacity of BPDs. He also segues into the social aspects of those BPD being compromised.
So he does address these three aspects or personality, emotional, social, and intellect. But he seems to go farther as he speaks of zero correlation between the intellect and the ability to act, which I would consider the emotional WILL. Ultimately in his analysis one can see a very strong Compartmentalization between the emotion and intellect where the emotional, like a 2 year old in his words, remains in control of the personality, even to their own detriment, with the obvious implication that this effects the social functions of the personality.
In mentioning a causal foundation he references a neglect of socialization between 2 and 4, but he merely throws this out as a possibility while maintaining that they (psychologists), really don't know. He also offers Dialectic Behavioral Therapy as the best tool for BPD to deal with their condition. Dialectic Behavioral Therapy utilizes four modules,
Mindfulness: the practice of being fully aware and present in this one moment
Distress Tolerance: how to tolerate pain in difficult situations, not change it
Interpersonal Effectiveness: how to ask for what you want and say no while maintaining self-respect and relationships with others
Emotion Regulation: how to change emotions that you want to change
One might see mirrored in these modules the same efforts one finds in programs like AA. Setting aside the alcohol is merely a preliminary step, ultimately the addict must learn to grow up, to be accountable, to be conscientious, as emotional immaturity is recognized as a root factor in the addiction. And it is not like many addicts don't understand intellectually that they are addicts, but there is, at the bottom of addiction just as with BPD, a separation between the emotional body and the intellectual body.
BUT, this is in terms of degrees, as with the psychiatrists I've worked with or the STEM community of which Wolfhnd speaks, degrees of separation can still exist. A person in the scientific field might be better socialized, intellectual efficient, yet still be stunted emotionally. They may know better than to throw tantrums at work as their image and job remain important to them, but that does not mean they don't express this emotional deficit upon their spouse or children or in any number of passive aggressive ways, even towards peers. BPD diagnosis just seems to cover those who are the least controlled in society, just as there are both functioning and non-functional alcoholics.