Like pretty much everything, borderline personality disorder has a poorly understood genesis, involving a complex interaction between biological and developmental components. There certainly does seem to be a genetic component. As Kriesman notes, “Family studies suggest that first-degree relatives of borderlines are several times more likely to show signs of a personality disorder, especially BPD, than the general public”(Kriesman, 2010). Researchers have found multiple candidate genes associated with various psychiatric problems, and rather than identifying a “borderline” gene, it is more likely that the cumulative influence of several gene variants, which code for neurotransmitters and neuroactive steroids, interacts with environment.
From a more immediately neurobiological perspective, structural and functional abnormalities have been observed in the brains of those diagnosed with borderline personality disorder, detectable through white and gray matter volume abnormalities, metabolic abnormalities, and brain wave abnormalities found in EEG scans.. Neural idiosyncrasies associated with increased emotionality and impulsivity, in particular, have been found, as well as structural and functional deficits in parts of the brain associated with rational thought. (Kriesman, 2010). Indeed, those diagnosed with BPD are much more likely than the population at large to have experienced various forms of brain injury.
From a more purely environmental and developmental perspective, borderline personality disorder may stem in part from a failure to establish an appropriate parent-child attachment relationship. This is true throughout the individual’s developmentally formative years. Some developmental theorists argue that BPD may result from parenting styles that resist the separation and individuation of the infant between 18 and 30 months. The other extreme, absent parenting, may also influence a progression towards borderline pathology (Kriesman, 2010). Fathers in particularl tend to be emotionally distant, and the mother may be erratic or psychologically disturbed in some way (Kriesman, 2010). Alcoholism, violence and incest are common themes in the formative environments of many borderlines (Kriesman, 2010). Oftentimes, there is a great deal of conflict between the child and the mother, in addition to an absent father.
While highly controversial, object relations theory has exerted a great deal of influence upon theories concerning the genesis of borderline personality disorder. The psychoanalyst Margaret Mahler has been particularly influential in this regard. For Mahler, the human’s developmental years consists of 7 phases which Kriesman (2010) articulates in the following way:
1) The autistic phase – state of pure, undifferentiated psychic oblivion.
2) The symbiotic phase – differentiation begins but others are seen as extension of the human rather than as distinct “objects.”
3) The separation-individuation phase – the individual finally begins to experience the world as a differentiated individual separate from the primary caregiver. During this precarious phase, the individual, on the one hand, still depends largely on their parents, but also desires autonomy. On the one hand, the individual is afraid of being swallowed up by the primary caregivers, but on the other hand, does not want to be abandoned by them. The borderline’s struggles with fears of abandonment and dependency are crucially related to this stage, as the stage involves the use of a highly primitive defense mechanism known as “splitting.”
The child must develop “object constancy” at this point in her life. Object constancy, in object relations theory, refers to the idea that, although a primary caregiver has left, this does not mean that the previously all-good caregiver has vanished and become an all-bad caregiver, but instead, means that the caregiver is temporarily absent but will return. Developing the latter attitude, which is capable of dealing with ambivalence and handling anxiety well, as well as dispensing with the defense mechanism of splitting, is a crucial formative process, and abnormalities in the development can result in borderline pathology.
4) The differentiation phase (5-8 months) – It is at this point that the child, primarily attached to the mother, exhibit anxiety towards strangers. If the mother is not supportive during this phase, a tendency towards permanent “splitting” towards strangers may develop, causing the individual to develop borderline pathology and violently oscillate between idealizing them as all-good an devaluing them as all-bad, as the borderline is wont to do.
5) The practicing phase (8-16 months) – The child begins to exhibit a desire for autonomy by alternating between exploring on its own and returning to its mother.
6) Rapprochement phase (16-25 months) – Object relations theorists see this as one of the most important phases when it comes to the possibility of developing borderline pathology. Ther mother must, at this point, encourage the infant to become autonomous, while at the same time providing the kind of support necessary to alleviate the understandable anxiety the infant has at this stage, with regard to individuation.
“The normal two-year-old not only develops a strong bond with parents but also learns to separate temporarily from them with sadness rather than with rage or tantrum. When reunited with the parent, the child is likely to feel happy as well as angry over the separation. The nurturing mother empathizes with the child and accepts the anger without retaliation. After many separations and reunions, the child develops an enduring sense of self, love and trust for parents, and a healthy ambivalence towards others”(Kriesman, 2010).
In the case of the infant who becomes susceptible to borderline pathology, the mother goes to either one extreme or the other, either encouraging or discouraging the union to an inordinate degree (Kriesman, 201). This produces extreme fears of both abandonment and of being swallowed up by the primary caregiver. Obviously, this is symptomatic of later borderline pathology, in which the borderline individual exhibits extreme abandonment anxiety, only to push individuals away if they come too close.
“…the child never grows into an emotionally separate human being. Later in life, the borderline’s inability to achieve intimacy in personal relationships reflects this infant stage. When an adult borderline confronts closeness, she may resurrect from childhood either the devastating feelings of abandonment that always followed her futile attempts at intimacy or the feeling of suffocation from the mother’s constant smothering. Defying such controls risks losing mother’s love; satisfying her risks losing oneself”(Kriesman, 2010).
7) Object constancy (25-36 months) – The absence of the primary caregiver, provided the child has progressed this far, is no longer a token of her abandonment, but is seen as normal, and, though it may produce anxiety, does not produce one that is so intolerable that splitting is required in order to alleviate it. The same is true of the mother’s anger. The mother being angry is not seen as the occasion of total abandonment, but as a normal part of interpersonal interaction. The child uses “transitional objects” such as teddy bears or blankets which
“represent mother and are carried everywhere by the help to help ease separations…Transitional objects are one of the first compromises made by the developing child in negotiating the conflict between the need to establish autonomy and the need for dependency. Eventually, in normal development, the transitional object is abandoned when the child is able to internalize a permanent image of a soothing, protective mother figure. Developmental theories propose that the borderline is never able to progress to this object constancy stage. Instead, the borderline is fixated at an earlier development phase, in which splitting and other defense mechanisms remain prominent. Because they are locked into a continual struggle to achieve object constancy, trust, and a separate identity, adult borderlines continue to rely on transitional objects for soothing”(Kriesman, 2010).
The child will continue to struggle with the anxiety involved in integrating the mother’s frustration with the mother’s love, and seeing her as a nuanced, complicated person with a life of her own, frustrations and joys of her own, etc. that have nothing to do with the child. Throughout adolescence, moreover, the individual must individuate in such a way that they have the sort of emotional resources to experience contentment apart from other people. They must not fall into the trap of having a merely reactive relationship with significant others.
“An insecure teenager may ruminate endlessly about her boyfriend in a “he loves me, he loves me not” fashion. Failure to integrate these positive and negative emotions and to establish a firm, consistent perception of others leads to continued splitting as a defense mechanism. The adolescent’s failure to maintain object constancy results in later problems with sustaining consistent, trusting relationships, establishing a core sense of identity, and tolerating anxiety and frustration”(Kriesman, 2010).
It is especially during the adolescent years, that extreme abuse from significant others may interfere with such healthy individuation, and give rise to later borderline pathology.
Kreisman MD, Jerold J.; Hal Straus (2010-10-25). I Hate You–Don’t Leave Me: Understanding the Borderline Personality (Kindle Location 1154). Penguin Group US. Kindle Edition.