According to Kernberg, healthy adult personality organization requires that these early positively and negatively toned object relations become integrated and organized into a cohesive whole. This is because the world is complex and cannot be accurately represented by emotionally polarized, simplistic representations. A healthy personality must be able to accommodate this complexity and to capture the diversity and nuance of emotional reactions that may be provoked. Therefore, people with healthier personalities, based on integrated objects relations, develop this fairly realistic and accurate view of themselves and others. They are capable of representing both strengths and weaknesses (good and bad qualities) at the same time. This allows for the ambivalent and contradictory feelings that such mixed qualities may provoke.
Less healthy personalities are based on persistently polarized, and not-yet-integrated object relations. They cannot represent something that is both good and bad at the same time. Instead, good and bad representations are "split-off" from one another. The best such a personality organization can manage is to switch back and forth from one polarized "all good" or "all bad" object representation to another. In so doing, they rapidly switch from strongly negative feelings, to strongly positive ones, and then back again. This disintegrated personality organization, based on persistently polarized object relations, is characteristic of individuals who are diagnosed with severe personality disorders.
Having fragmented, extreme, and split-off, self-other representations interferes with a person's ability to develop a consistent sense of self, and a consistent sense of other people. Frequently, people with these split-off representations of themselves do not feel like they are the same person across time and situations. They may feel very differently about themselves and their lives from one day to the next. Similarly, they perceive their relationship partners as having very different qualities at different times. It is perhaps not at all surprising that such individuals would act in ways that reflect their changeable perceptions of self and others. For instance, an inconsistent sense of self may mean frequently changing careers, relationship partners, living arrangements, and even life goals and values. Under such circumstances, genuine intimacy becomes elusive.
It may be difficult to imagine what a disintegrated personality organization would feel like if you yourself are in possession of an integrated personality organization. By way of illustration, suppose you have a friend who is very honest and forthright. You value your friend's honesty because you know you can always count on her to "tell it like it is." However, sometimes the blunt way she delivers this information seems a bit insensitive to you. You might reflect on this relationship and say to yourself, "I sure do like my friend's honesty but I'm not always so fond of her bluntness." However, disintegrated personalities would experience this friend quite differently. In one moment, they will be completely in awe of their friend's honesty, and head-over-heels enamored with her. In the next moment, as they begin to experience their friend's insensitive delivery of information, they will completely despise and hate her for hurting their feelings. This is because people with disintegrated personalities simply cannot experience both the good and bad qualities of a person simultaneously. At this point, it is fairly easy to imagine that such rapidly shifting experiences of self-and-others causes some very intense feelings. These intense feelings may lead to extreme behaviors that often result in conflict and disillusionment. It is also possible to imagine the hurt, anger, and confusion that are felt by the other people in relationships with these disintegrated personalities.
Consistent with this theory, Kernberg would view someone with Borderline Personality Disorder as having persistently primitive (e.g., developmentally early) internal object relations split-off into "all good" and "all bad" representations. At any given moment, this person will operate from one of these polarized representations or the other, but not from both at the same time. Mixtures of contradictory feelings (e.g., like and dislike) occurring at the same time are experienced as intensely disorienting and anxiety provoking. This anxiety and discomfort prompts the person to keep such feelings "split-off" from each other, and separate. While temporarily reducing anxiety, this splitting prevents the person from experiencing affectionate feelings and aggressive feelings at the same time. Because the person cannot experience conflicting feelings simultaneously, it prevents them from integrating representations into a cohesive whole. This, then, leads to intense feelings and behaviors that interfere with their functioning.
A highly effective treatment for personality disorders, based upon this theory is called Transference-Focused Therapy.