It's also sad that some people turn psycho after getting married and use the children as little more than pawns.
Sadly, in most cases like that, it's the women engaging in the vicious behavior.
They have they greatest incentives to do so as men and women are not equals before the law. I'm sure the opposite would be true if the roles were reversed.
I don't think marriage turns anyone psycho. I think they were psycho before the marriage & the people marrying them turn a blind eye to it. Both genders are quite capable of being guilty of the kind of vicious behavior you talk about.