When I was 6, I just wanted to be loved and appreciated. I learnt very quickly that I was not loved. A hard lesson to learn. I lost faith in my parents. A trauma at 8 years old, left me with some nasty triggers, but no one talked to me about this stuff like the grown up I had to become. They just tried to keep me quite and did not allow me to be upset. I was even hit if I cried about it.
I guess, it depends on what the trauma was that your son when through. I think that most people think, when a child is angry, they need to stop them right away. But emotions are how we learn to deal with things. Maybe, doing the opposite would help, like getting one of those blow up punching bags, so that he can get his feeling out in a healthy way.
Kids, don't really know how to deal with feelings, and they don't know what they mean, they just have them. So getting the feeling out in a healthy way can be quite therapeutic. I never had a pet, wasn't allowed, but in my teens, the neighbours dog became my best friend, and I would talk to it about everything.
I withdrew from other kids, I did not like getting singled out, did not like getting laughed at, did not like getting into trouble. I didn't have friends. I would sit and imagine my own world a lot. I figured no one wanted me for a friend, and friends just got me into trouble so I was better off without them. When badly triggered and scared, I would pee myself, which resulted in being laughed at. I did not like that.
So, the earliest age I remember isolating was really that young. I did want friends, but it was not safe to have them. My teachers were no support, they just treated me like a kid, I wasn't a kid any more. I had worked out that at a young age, I was not loved or unsupported, or cared for and I was forced to suppressed everything - so adults did not know anything, and I kicked at them because they did not realise that I knew more than them about the real world...