I believe there are several basic motivations to lie when you have BPD. There are also two types of lies: by admission (by telling) and by omission (by not telling). Both types are a problem with someone with BPD. The motivations for telling a lie (or omitting truth) by someone with BPD are as follows:
1. When it is more painful to admit or tell the truth.
2. When she wants the other person to think “better” of her than she thinks of herself.
3. To avoid the judgment of the other person or judgment of herself.
4. When she can’t see the “truth” because of emotional reasoning brought on by the refractory period of the emotion felt. In other words, when feelings = facts.
The first three of these factors play a role in the lies of someone with BPD and they are often inter-related. If the person to whom the lie is told is likely to judge the person with BPD as “bad” or “deficient,” the expectation of disapproval triggers first rejection sensitivity and then shame, because the person with BPD actually feels deep inside that, if she admits the truth, the other person will “find out” that she is a “bad person” and reject her fully. The last motivation is “emotional reasoning.”
I bring up these motivations not to “let liars off the hook” but to point out something: a person with BPD does not live in the same “reality” as you (the Non) do. Your truth is informed by what you see, hear, experience and what you believe about those inputs. A person with BPD is most often informed by her feelings about the experiences. These feelings can be misaligned with the facts and, as Paul Ekman notes in Emotions Revealed, a person overcome with strong emotions “cannot incorporate information that does not fit, maintain or justify the emotion.” In effect the original lies can be motivated by the inability to see information that doesn’t support the feelings. When someone is emotionally dysregulated, she just can’t see the truth if it doesn’t match what she is feeling.
In effect, she is not really “lying,” but merely pointing out “facts” (or generating them) that support her overwhelming emotion about the situation. The subsequent lies, which are used to “cover up” or support the emotional reasoning, are typically done for one of the first three motivations, particularly the idea that you would think of her as less of a person (and deservedly so) if it was revealed that she lied in the first place. I think there can be some argument about whether deep-down a person with BPD really believes the original lie (or any of those generated by motivation number four) when she exits the prolonged refractory period. My suspicion is that deep down a person with BPD is more concerned with the pain and shame the revelation of the lie will cause her than with repairing, rather than repeating, the lie.
While it is useful to know the motivations behind the lies, it still doesn’t make the lies any less hurtful. Being lied to is a painful and hateful experience for the Non. It destroys trust and personal integrity and leads to suspicion and paranoia. When someone specifically lies to you (by admission) or is secretive (by omission), you end up feeling angry, saddened and disconnected from your loved one with BPD. It is a confusing, embarrassing and painful experience.
Each of the motivations can be removed by:
Number 1: Pain management, distress tolerance (when the pain can’t be removed) and self-soothing
Number 2: Self-acceptance*
Number 3: Self-acceptance and developing the ability to tolerate judgment
Number 4: Emotional modulation
* a quick note on Number 2. I have known at least 3 borderlines rather well in my life. I have also known about 3 more peripherally (and of the 6 – not including my wife – 5 are female). But the 3 that I have known well (2 women and 1 man), ALL of them used motivation #2 to generate seemingly outlandish lies. Sometimes, each of them would have to “own up” to the lies and that was a painful experience I’m sure. I know if I every have to own up to lies, it is painful for me. I can only imagine how painful it is for someone with as much shame as a borderline feels.