[Xichekolas]

While that is certainly possible, I wouldn't argue it's required.

Consider a couple that is living together. They might be unhappy, but bearing it anyway because they have a lease and moving out and separating all your stuff is a pain in the ass. However, once that lease comes up for renewal, suddenly the burden of breaking up isn't so heavy, which might be just enough to make it happen.

What I was proposing for marriages->jobs is analogous.

[electromagnetic]

There does seem to be a lot of people (males and females) looking for an excuse to escape a relationship. Honestly I believe many of these relationships are already failed because both parties have essentially quit but are 'going through the motions' and when the 'motions' change then it becomes easier to quit than adapt, just like it was easier to stay together than split.

This behavior just reminds me of the concept of a philosophical zombie. They seem to make the choice not through conscious thought but through unconscious programming.