Actually, things tend it change if one of them cheated and there's proof of it. My friend's mom cheated on her dad, and he had proof of it. When her parents got divorced, her mom really didn't get anything she asked for except child support. It really just depends.

Except in "no fault" states. I had proof of my ex husband's adultery, but it had no effect on the divorce proceedings. The fact that he was physically abusive didn't give me any leverage either. Everything was split 50/50...or would have been if he had shown up to the final hearing. It sounds unfair, but it's for a good reason. I lot of people have been murdered by their spouse because the spouse wanted out of the marriage but would have lost everything in the divorce because they committed adultery or abuse or what have you. "No fault"states reduce the chances of that happening.

No fault divorce law also lets spouses kick deadbeats and gold diggers to the curb without invalidating prenups.