Father in law screams at mother in law for no reason

You're in a bad position, unfortunately. Because your FIL might start to see you as an outsider, or turn his wrath to your wife. Of course you don't want either of these things.

Is this behavior recent, or has it been going on forever? If it came on fairly recently, then a trip to the doctor is in order, to address anything which might have caused a personality change, e. g. a stroke, a brain tumor, etc. And if those things are ruled out, or even if it's not just a recent phenomenon, then you can frame it as making sure your FIL is okay. Some people accept what is essentially an appeal to authority.

Also, is your FIL an immigrant? I ask because some of this may be culturally based. Not that it is acceptable anywhere, but if this is how things were always done on XYZ Island, then maybe the appeal can be that things aren't done that way in America (from your username, I assume you're in the US).

If you have children or are planning on same, you can also frame it that way, that you will not allow them to be around this sort of behavior. And so if you are visiting for a week, you pack and you leave, even if the yelling starts on Day 1. That doesn't help your MIL so much as it sends yet another message to your FIL that this is unacceptable.

Support your MIL as well as you can. Maybe your wife can take her out for a day of fun, or you can bond with your FIL for a day of fishing or go to a game or whatever it is which will work. Keeping them separate will improve her life, to be sure.

And if it ever comes to violence, I hope you'll take your MIL out of there.

This is not an easy situation. If your MIL wants to stay married, then you have to kind of work around that. But, at bottom, your responsibility is to your own household. Keep your wife and yourself and any future children safe and out of that kind of a toxic environment as Job One.

Jespah, thank you for your reply. I agree with everything you said. Let me answer your questions.

His behavior has always been like that. Recently it got a little more intense. That is why all of us are on edge and we strongly want this to change.

No, my father in law is not an immigrant. He is as American as apple pie. He kind of has this attitude: That's just how I am.

I know that his parents acted like that. Especially his dad. That is learned behavior.

The bonding wit my FIL I tried. It didn't work. He is not able to have a conversation that is more in depth. He is not capable of sharing a feeling. He mumbles things to himself. To be honest, I don't feel comfortable with him.

If it would come to violence, I would get my MIL out of it for sure. The verbal insults I consider as abuse!

I agree that my responsibility is with my family. I will protect my family no matter what!

Thanks again!

I feel for you. And if you don't feel comfortable with him, and I assume your wife is kind of in that camp as well, then your natural desire is to just avoid him. Which helps you but doesn't do anything for your mother in law.

A lot of people who are abused seem to have such pancaked self-esteem that they think they deserve it. Or she might be rationalizing it as being okay because he doesn't hit her, or because she's put in so much time already (that's a kind of sunk-cost/gambler's fallacy, that the more quarters I put into this machine, the more likely I will get a payoff because I deserve it because I've invested so much time and money already), or she feels she can't start over again.

Or, the world might scare her. I don't know anyone's ages, but I'll give you a for-instance from my own life. My parents get along wonderfully. They are also in their mid-eighties. My mother is a smart woman (as in, she has a Master's of Library Science), yet she has clutched my sleeve, more than once, and said to me, "J___, if your father goes before I do, please promise me you'll handle paying the bills and the taxes." And of course I say yes because I love them both. It's not that she doesn't have brainpower; it's more that it's something so new and different for her because my father has always taken care of this.

I write this not to rat out my mother (God, I hope I'm a better daughter than that!), just more to give an example. Maybe some of that is the case with your mother in law? I'm shooting in the dark here because I don't know any of you, but that might be a fear, that she feels stuck and makes the best of it because to change seems so horribly daunting.

So the question is, how willing are you, your wife (and I think you said you also had a sister in law?), etc. to build her up, tell her she's valuable and worthwhile and loved (which is lovely for anyone to hear), and see if you can help give her tools to be more independent (or find a place where she can get life skills or the like). Not necessarily to prepare her for a separation (although that or a divorce would probably be the best things that ever happened to her if she went in that direction - but I wouldn't bring that up with her if I were you), but more to be more self-reliant. She will feel better and more likely to not take his crap if she feels she's valuable and smart, etc.

Sigh. I don't envy you. You're a good guy for caring about what happens to her.

Talk to MIL. Is she afraid? Is this even worse when you aren't around?.

His behavior also sounds like dementia behavior.

Your MIL needs to tell his Dr about this behavior.

While this has been his temperament all along, it sounds like its moving into abuse or even violence.