What Causes Borderline Personality Disorder?

Updated: Jun 17, 2019

You've read many conflicting things, now here's the truth.

Imagine you are two, or three, years old. And imagine that every time you express your feelings, your parents subtly invalidate that emotion.

For example, the air hand dryers in restaurant bathrooms scare you to death. They’re loud and terrifying, and they cause you to cling like a tick to your mother for help. But instead of comforting you, your mom laughs at the ridiculousness of it and tells you to stop being scared. It’s so amusing to her, in fact, maybe she keeps turning it on because she just can’t get over how scared you are, and to show you why you shouldn’t be.

Or, let’s say that at two years old, you're playing with a bottle of honey you managed to snatch off a table. (Or your mother's makeup. Or a tube of children's goo.) The honey, or makeup, or goo, is now all over the floor, and all over you. As your father comes into the room, you look up at him, laughing, as gleeful as can be. Horrified, he barks, “What are you doing!” as he snatches the bottle from your hand.

Your emotions just went from the heights of joy, to zero, in a split second. Or, you can’t find your baby doll’s shoe. You have one, but can’t find the other. This makes you frustrated and sad. “Oh stop crying, that’s no reason to get upset,” your parents tell you. And if you’re still crying five minutes later they say, “Keep that up and we’ll give you something to cry about!”

A few isolated instances of this sort of invalidating behavior would probably not cause any damage. However, these types of parents are not generally one-time offenders. During the relatively brief window of development when children are forming fundamental certainties about themselves, and about the world, consistently having their feelings invalidated over a period of time has two disastrous results:

First Disastrous Result

The child subconsciously arrives at the conclusion that his or her feelings are inherently irrelevant and shameful; devoid of worth.

This is a completely logical conclusion, based on the attitude his or her caregivers consistently display in regards to the child's feelings. This rational, yet subconscious, conclusion that the child arrives at is what is referred to as a distorted core belief*. It is distorted because, although it is a relative truth, given the child’s current circumstances (in his family, his feelings really are irrelevant and treated as if they are shameful), it is not the broader truth. It isn't the reality of the inherent nature of his or her feelings. The child’s circumstances will also one day change (adulthood, his or her own relationships).

It is core in that it involves a fundamental (foundation) conclusion of how life and the world work, and the nature of self. Such fundamental, or core, conclusions are arrived at relatively quickly for use in getting started at navigating life. They get filed away and never questioned again. Future beliefs, or knowledge, will be layered over this and directly influenced by it – which means all of those conclusions have the potential to end up distorted as well.

Second Disastrous Result

The child stops volunteering emotional intimacy (emotional honesty) to his or her caregivers, as well as to others.

This will continue throughout the child’s entire life. The child will live his or her whole life in total solitude with his or her authentic emotions. He or she will keep them safely private and out of reach from family, best friends, girlfriends, spouses, lovers, and children. This will translate into severe intimacy deficiency, cold marriages, inability to feel empathy, lies, secrets, double lives, a fierce unwillingness to even consider seeking out help from others (his parents’ behaviors taught him it will only lead to rejection of his feelings, embarrassment, humiliation, and shame).

This is also where the personality-disorder part of the disorder comes in. Instead of feeling comfortable enough to allow their true personalities to show (which is really just another way of saying that you are open with your authentic feelings), and therefore mature, those with Borderline Personality Disorder keep them hidden, and instead try to give everybody a superficial version of themselves, which they believe will be more readily embraced. (This is in fact the explanation for the ‘mirroring’, or 'chameleon', aspect of the disorder you sometimes hear referred to. Because they are ashamed of their own authentic feelings, which is something that is inseparable from one's ‘authentic identity’, folks with the disorder instead observe the personality traits of other people, such as celebrities, who they consider to be well-liked and accepted, and borrow aspects of their personalities superficially, in a subconscious attempt to improve their own odds of greater acceptance and admiration.)

All of the naturally-occurring effects which sprout directly from the distorted core belief, and thereby, the two disastrous results I’ve just detailed here, are what is known as Borderline Personality Disorder.


Not long ago, I discovered that my 3-year-old daughter is terrified of the air hand dryers in public bathrooms, which is why I used the example here.

I don’t need to know why they scare her, or make her understand that they aren’t scary. Scary is a relative thing, and to her they are scary, this is all that my primary concern needs to be.

I don’t think it is funny when my daughter is scared for any reason, and her fear is not more valid if is caused by say, an alligator, rather than by a hand dryer. In both cases, her fear is equally valid. So I validate her fear by taking it seriously and comforting her.

*Footnote: A second distorted core belief which sprouts directly from the first is If my feelings are irrelevant and shameful, then I myself must also be inherently irrelevant and shameful. Because your feelings are you. They are what make you you.

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