Live in the moment by splitting those legs
That is what its all about
Splitting is what happens in infancy. Mother is there when baby is crying- Good Mommy. Mommy walks away from baby when crying- Bad Mommy. This process of splitting, starts to resolve itself once the child begins to consistently get its needs met, in a healthy manner. Trust is formed, and the child knows that mommy will always take care of what it needs.
When needs are not met however, and the infant is neglected, or abused, or live under arbitrary rules- not being able to predict or trust what will happen under the care of others, the splitting gap does not close up. So splitting will continue to occur in relationships that require intimate trust in milder cases, or more severe cases- with anyone who comes into regular dealings with the splitter.
Idealization comes when needs are being met- The greatest man/woman to walk the earth.
Devaluation comes when perceived betrayal, neglect, or abandonment occur- Fucking most evil cock sucker/cunt licker to ever walk the face of the earth. :D
What you describe above just seems like a dysfunctional cycling. You know the relationship won't work, but you don't want to be alone. Denial or selective memory, comes to mind more, for your example. And yes, could be said to be living in the moment, very lazily and conveniently.
But it is not an example of the extreme nature that is splitting. Where one day your best friend understands you as no other person could, and is the only person you have ever been able to trust, and the next day she is the snake that turned her back on you when you needed her the most, and can never be trusted again. That is splitting.
Splitting is based on a perception that is warped. So like: Your best friend had good reason for not being there when you needed her, but because of feelings of abandonment, the perception gets bent, and cannot see past emotional turmoil, so the mind lies and makes of it something extremely negative, when in fact- the object the splitting was directed at, was not abandoning, but simply caught up in his/her own problems and needs.
Yes, relationships can, and often do, begin with idealization. To the extreme, it is more to do with grandiosity and narcissism than the start of black and white thinking. If that same relationship ends in a crash because of conflict based on real "bad behavior", or simply because of lack in compatibility, that is not devaluation. It the reality of two people who still need to explore, learn, and grow up enough to build a structure that will give them longevity.
When it comes to personality disorders, it's not always easy to make the call on what happened, because their perception of the relationship is usually distorted the whole way through, as the perception of themselves is also distorted. But you can be sure that without a lot of work, self awareness, and experience; disordered couples will usually crash no matter of whether what happened in the relationship was baseless or concrete. Personality disorders seek out that which will validate their disordered nature... not the part of them that is not disordered- and so I think it is more common than not, that real abuse and splitting occurs simultaneously.
Well that is rather broad isn't it? I mean, people change over time. Their minds deteriorate, and so do their bodies. So someone who might have been worthy of the title "trustworthy' at one time in their life. might, with age and other more extreme factors, end up with a corroded mind that will now do things so deceitful, you may see them as a complete stranger.
If what changed your mind about someones worthiness of being your mate is something trivial. like forgetting your mother's birthday one year out of twenty... I'd say you're just looking for a reason to be rid of them. If however, you decide this because your mate was caught cheating... that is valid... and anyone who tells you that it is not enough of a betrayal to call it quits- is the one doing the devaluing. Some factors for breaking up, are things that should only be allowed to happen once. If a relationship has turned to poison and both parties are miserable... it is only right that it should end.
I just hate psychodynamic theories with a passion. I'm a psych student and I know how and why all this is BS and it's just so tiresome people still believe in it.
If I could go back in time and kill Freud I would.
Science good, pseudoscience needs to rot.
Sorry, I've very protective of real science. Is my weak spot I guess.