terpe, you wrote the important circumstance to happen when opposites poles comes to clash on/collide. In relationships, whatever difference, we come to a point of compromise. Afterall, we all came from different genetics, race etc.. Personally, i tend to believe it's how much the either one can compromise to make the relationship works for both of them.But then again, I think in the longer term, that opposites could really clash when it comes to values,
and personality.
The characteristcs like personality, values attitudes and even religion tend to come out later as a relationship
develops and progresses to something more settled.
People who have a lot in common tend to have successful relationships. After all, relationships are all
about satisfying our own needs, most often at the sub-conscious level.