When I was about six, I witnessed my dad trying to smother my mum with a pillow while she was lying on her back on the bed. He had chased her up the stairs, and I don't know if he pushed her on the bed or hit her or anything. I went to see what was happening and I clearly remember her lying on the bed with him holding one of the pillows over her face. When I was about 12, we were on holiday in the South of France and I was having some difficulty with the memory. I was acting off, and Mum asked me what was wrong. I guess I must have made an indication, although I can't remember what I said, because she looked at me and said "You do remember, don't you?'
When I was ten, I witnessed him chase her up the stairs while she was screaming. I don't know what happened when they got up there. I was sitting in the dining room.
There were many other incidents over the years where he absolutely lost it with her, and although those were the only two physical incidents I witnessed, the temper loss would have him totally out of control and look very much as if he was going to turn violent.
Effects? I'm not sure I know all of them. I know I felt very different from my classmates, and isolated. I felt like I was "lower" than them in the pecking order. Only recently have I identified those feeling as what they were, shame.
I think that the atmosphere we grew up in destroyed my relationship with my sister. We turned against each other, not to each other. We didn't repair things until I was in my forties. We're close now, but we missed out on a healthy sibling bond for decades.
I have always suffered from low confidence and I'm sure it was from growing up in such an environment. There were many nights when I would dream that I was screaming, and wake up kind of fighting to scream. I now know that the temporary paralysis while we sleep prevented me from screaming out loud, but if we didn't have that, I'd have woken up screaming quite regularly.
My mum was an absolute sweetheart, and his treatment of her broke my heart. And she continued to love him, too.
While I have thus far avoided male violence in my life, I have nevertheless been very drawn to men who were horrible to me, bad men. Married one, too. He was nice beforehand though, but turned out to be highly emotionally abusive. But there were many red flags, and I guess I ignored them because they seemed familiar. Dad never liked me much either, and would lose his temper with me occasionally too. Sometimes badly. I do remember him hitting us quite badly once over not much, holding us by the arm and kind of swinging us around smacking our backsides, and when he tried to come in the room again, I remember screaming "No more!" Again, I was only about six. Our crime had been to not want to stay at the community centre alone to see a film while Mum went shopping in the same complex. I remember being frightened to be left alone. We were obviously way too young.
Given my bad choices, shame, and low confidence, I would say it has had a really bad effect on my life, and the only positive really is that I have avoided the physical side of domestic violence.
I'm in my fifties now, and my parents are dead. I don't think about that part of the past much anymore, but I'm still prone to a bit of shame. I definitely don't feel as "good" as people who come from "nicer" families. While my dad was a university professor, deep down he really was a common thug. Due to this shame, probably, I make myself very Charlotte-esque, from Sex and the City. Trying to make myself look "better" than I am, I suppose.
I also still struggle with confidence on occasion, although nothing like as bad as I did when younger and they were still alive. I think those feelings are part of me.
Most of all, I mourn that I never had and what I deserved - a nice daddy - and that my background probably contributed to me marrying a wrong' un, which fucked up my life in all sorts of fabulous ways.
I do hope this helps you.
ETA: Eventually, not long after I'd finished uni, he threw me out of the house for spilling coffee on a computer keyboard. I hadn't yet managed to find a job, but I found one quick - a wrong job, and remained stuck in it for nine years as I couldn't go and train for the thing I wanted to do. There was no way I could afford that on top of all my rent and bills. And I had to flat-share with a stranger I found in the newspaper. If he hadn't thrown me out at that point, I'd have been able to do my post-graduate course and had a much better career. I finally managed to do it when I got married, and have now been in the field for quite a few years, but am nowhere near where I would be if I'd been able to do it out of uni.
He never liked me, or my sister, and I have no idea why he had us. Probably just because Mum wanted us.
I still looked after him when he was old and dying, fool that I am. Just goes to show how fucked-up the family bonds forged in violence really are.