I think there are some emotions that tie men to women whom need help. I dont think men necessarily go looking for the woman in distress. And typically the women that turn out to be head cases that need constant "saving" become too burdensome and men try to dump them just to get away.

It's hard to explain but I do think it's in men's natural makeup to take care of a woman. And there's a strong emotional bond that forms when a man does that. It's kind of twisted, especially when women take advantage of it and ride that poor boy for all he's worth.

As for women with kids, I would guess the majority of men would prefer not to deal with another man's children.