im gonna make a bigger response in the morning, particularly about BPD vs NPD cause I think it's incredibly interesting how the two disorders are related in some way but so different in others and how depending on I suppose what season/episode you are watching, Nicki does seem to be leaning towards one more so than the other
as for what causes BPD
yes, it definitely imho is a combination of factors - the first of which is a newborn/infant/toddler that has an exceptionally sensitive temperament (often BPers are said to have 'no emotional skin'). The first few days/weeks of a childs life are so crucial particularly to those with this temperment that any percieved or real abandonment (emotionally, physically or such) can cause such discomfort and shame and stress in a child that they literally are unable to cope and being infants with no real understanding outside what it is they feel inside can become besides themselves with anger and rage - which is a method they develop to cope with the pain and shame and guilt they feel at not having their emotional (and physical in cases) needs met at that critical period
it's called "the core wound of abandonment" and it's not always easy to trace in every individual who develops BPD, but it is a central figure in the false sense of self or identity the child then creates in order to simply survive from day to day. pushing away pain and fear and terror and numbing oneself to a terrible outside environment (unforgiving/unloving/directly abusive or coercively so) is crucial for the child/toddler/infant to learn to do in order to not simply implode so to speak
like, for nicki, she is one of how many children of Roman? and how many of adaleens? She is certainly not the oldest, and she is a daughter which from what I sort of see in the show, makes her less 'worthy' of as much attention/time/education as say an older male child.
the writers do not show us, so i'm only assuming that perhaps she was simply just one of too many infants/babies and was not properly cared for in those first crucial moments of development. I know for myself, the day my father and mother brought me home from the hospital, that night i was crying to be fed (or some other such need) and my mother explicitly stated out loud to my father that she simply did not want to bother getting up to take care of me. I was her second child (first one with my father). My father did step up and take over what would more often be the 'mothering' role.
of course my father has his own issues and is not a very emotionally accepting or supportive person, at least back when i was very young - so while my physical needs were met, i was left without anyone to console me if i simply just needed as a child, physical contact, a soft word, or a hug. My father worked full time so more often than not my first two years were spent living inside a playpen during th day, or a crib at night, screaming/crying/filthy/hungry while my mother sat stoned off of her rocker watching tv.
obviously that's my expereicne and i am very aware of how it has pretty much destroyed my ability to form attachments (healthy ones) because I absolutely do not trust another individual to have my best interests at heart - the moment someone may do something that seems threatening or that may indicate that they are abandoning me, i go into this state of sheer panic and terror and will be on the floor in hysterics screaming for them not to 'leave me' when in all reality, often times my father simply wanted to just go upstairs to make a phone call. to me, him leaving a room that i am in without telling me why, was ALWYAS because i must have done something to deserve 'this abandonment'
that was straying - but for Nicki if she did not have that ability to closely connect to a caregiver and trust uncondtionallly that they are safe and worthy of attention and comforting - then they develop like i mentioned what is considered a false sense of self which is often considered to stem from the notion that one must be evil and shameful.
so other people have become unsafe, you can't trust them, they are (in your experience) inconsistant with you and as a child this is a terrible reality. BPD is often referred to as a relational disorder. It's sort of a catch 22 in that all the BP really wants is that care and concern and ability to bond with other individuals that was denied them as children - but in trying to achieve this in older years the traits they have ingrained in themselves (distrust, over controlling, deciept) often make the relationships one seeks out either replica's of the truamatic relationship that started the whole thing (perpetuating cycles of abuse) or will turn what could be a healthy loving relationship into an emotional 3 ring circus where the nonBP partner is usually the target to rage the BP inhabits, and then the partner may become overwhelmed or upset or offended because they didn't do the initial damage yet they are being treated as if they were.
its not that the BP person does this intentionally, it's part of the process of losing ones sense of self as a child and to trigger and flash back to incidents that have occured back then, while actually living and being in the 'real world' that is your adult life. so i know that when I have gone into episodic rages or break downs at my father - while yes he is partially responsible for the initial abuse/problems - whatever it was he might have said or done at the moment is NOT worthy of the reaction I will bring at him. it is something i honestlycan not (or could not until recently) help because i often could not see it coming
Nicki rages at Margie over her speeches. I do not for one think that she intended to rage and get up and flip a chair and storm out. She may internally always have intended to make it a confrontation - to accuse her of being selfish and lying and for being ungrateful for the help she and barb have given her. it may have been every intent to simply say these things allowed in an adult and calm fashion. the problem is, once faced with a negative response or in this case, margie's defensiveness, instantly she withdrew back to her old childish self and basically threw a temper tantrum.
the issue of whether she was correct in her "side" that margie should not have been doing what she was doing, isn't as important as how she handled it. i mean, yes, she had a right to feel rejected and glossed over and taken for granted, but whereas an individual with healthy coping and relational skills may have been able to keep it at a conversional level - she instantly "threw in the emotional towel" and screamed and ranted and tossed her 'toys' around them stomped off like a child. its what she has always done and it is easier for her to deal with the anger that came up inside herself, than it would have been to deal with the realized pain she feels that maybe margie is correct in some aspects
its like she goes looking for crisis, or jumps into something that has the potential to turn into one with the intent to make it so. it's so hard watching the few scenes with her breaking down in front of barb or bill about how damaged she feels, that she doesn't know who she is, and then getting interrupted or essentially 'hushed up' because she's literally waving the white flag in their faces telling them she knows she is not acting "like a normal nicki unaffected by growing up at JC" and that she wants differently. well if she is being unintentionally snubbed or brushed aside in moments lke this it just reaffirms to her that she just maybe isn't worthy of being that nicki and to push it all back inside and numb it out.
so uh - yeah, thats WAYY in depth and like i said, how i see it - mostly her behaviour of the fourth season.
to be brief - a child is born with a predisposition to be overly sensitive and maybe what some parents consider 'too needy' as infants - so if they do not learn to feel valued and taken care of and can put their lives in the hands of others without the terror that doing so will result in death (not just physical but emotional death) then it is very possible they will grow up to develop this disorder. it's pervasive and involves learned maladaptive coping skills that you develop over the years which is why it can not be cured by a pill or by therapy alone. there is a lot involved in changing ones completely way of thinking and relating to life/situations and unfortunately i do not see Nicki in the position to be able to find help for herself, not while living in such an environment that still seems to constantly reaffirm all the negative things she learnt growing up
often there is more tangible abuse like physical, sexual or neglect that occurs sa well, since very young kids/toddlers simply can not fathom the betrayal of their caretakers (even if it's a stranger, they are still considered a care taker in the eyes of an infant) but it is not 100% and some people can develop this disorder without clearly knowing how or where they lost their sense of self growing up or where the core wound of abandonment came about. (or when - as it's oten referred to as someones emotional age - the age at which they become arrested emotionally). i myself am 25 chronologically but emotionally i can revert back to a toddler who's screaming hysterically and gripping onto my fathers legs as he leaves me yet again day after day at a baby sitters that was abusive on multiple levels. i never did and do not still to this day completely trust my dad to 'save me from harm' even though rationally i know he never meant for me to be such. so i shut it down, i didn't talk about it and gave up trying to be 'saved' and just accepted that it was what i was meant for/deserved.
to this day if someone in my life even a casual aquiantance is frowning in my presense my gut reaction is "are you mad at me". it's my mantra. it is so critical to my survival, to know if thsoe around me are intending to do me harm, that i have lost SO MANY people i love due to the fact htey jus tcan't handle it.
nicki is trying so hard right now to connect to bill and to express some of the fears/insight that she is coming to terms with and if he keeps rejecting her feelings and saying 'it needs to be put to bed' or with alby saying it should be left in the past, im afraid she will never be able to heal from the trauma of her past and will continue to act in 'nicki-esque' fashion.
Woo boy that was long ans im sorry for the spelling mistakes. laying on my bed typing at 5am. if i sort of touched on something but didn't fully explain, let me know... or if i said something and you want to know more about its relationship to nicki's character from my POV, also let me know
JB