>The theory is that there's nothing more disturbing for a boy than to see her mom with different men as the boy grows up
That's an absurd theory. Anyone who's actually spent time around single mothers would have observed that they many have more difficulty discipling male children, and lack of discipline is what causes boys to grow up into criminals (as we see with boys raised by two parents who fail to discipline them).
But a couple where divorce is not a legal option is not a "stable couple", so you're effectively arguing against a strawman.
Here's what usually happens when divorce is not legally allowed:
1- The divorce happens in practice, with people splitting and/or taking lovers. Is this "stable" in your opinion?
2- The divorce doesn't happen even in practice, and either the man, the woman, or both, are stuck in a loveless, unhappy marriage that also causes harm to their children. I know you don't consider this "stable" so I won't even ask.
3- The divorce doesn't happen and the couple eventually makes up and manages to make it work.
You're betting everything on option 3, but it doesn't seem to happen all that often. Most common are options 1 & 2.
In other words: divorce only gives a legal option for problems that exist in couples since the dawn of time. Taking divorce away doesn't make those problems go away, it only makes people unhappy and/or they go about their way in illegal ways.
The problem with these childhood trauma theories is that there’s an obvious genetic confound. If your biological father abandoned or abused your mother, you also share 50% of your DNA with a man who abandoned or abused a woman.
If there is a childhood trauma explanation, I think it has a lot more to do with stepfathers being far more likely to be abusive.
