Children who are abused or who experience domestic violence learn this behavior from adults who take it to the extreme. Parents who think it is acceptable to spank and slap their children are modeling the same behavior in a milder form. They teach their children, by example, hitting and hurting are acceptable if one does not hit too hard or hurt too much. It is the same unacceptable lesson for their child, though. Be sure you are not teaching this behavior to your child through hitting and hurting him.
If you observe the sign in your child, develop a strategy to stop your child from hitting and hurting without your becoming aggressive with him. Your intervention should follow this progression:
As with other behavior problems, your setting a good example for him is essential; and insist everyone in your family does the same. This will likely require your teaching others to back off when he gets upset and angry. No, this does not mean he gets his way. It only means everyone agrees not to push when he cannot control himself. Your youngster will calm down after a while. In the interim, everyone should try to stay out of his angry space.
As a parallel process, try giving him small rewards for good days, days when he does not hit or hurt. A treat, special privilege, or something he wants all help. The key is to use negative reactions very sparingly. The payoff for your child needs to be for appropriate behavior, for not hitting and hurting.
Take extra care to be sure you do not omit this additional step. Always make a point to talk to your child after he has behavior difficulty. The approach is to sit quietly with him while he calms down. You can then talk about his angry feelings and how he managed them. He needs to learn to pick up on the clues he is about to lose control.
Say, "Once you get angry, stopping is very hard. You can learn to stop; but it's tough. It's easier to stop if you catch it before you lose control. If you can figure out when you first start to get upset, that's the place to control it, the best time to manage your anger better and come up with another way to express it. When did it first start getting to you?"
Your goal is for your child to spot situations and people that set him off. The best time for him to get control and to learn emotional management is while he still has control. As he learns to anticipate situations, his control will get better.
If your initial efforts are not successful (or exceed your capacity) and if your child's behavior is not improving, getting specialized help is essential.