Your HG 9 year old may have the introspection and cognitive tools to try more sophisticated control mechanisms. My DS7 has it much more together than I did at that age or 8 or 9 or 10 or 11; but I can speak from my personal experience.
Theory...
Part 1: Fix a weakness with a strength.
Part 2: You cannot easily fix the scale of reaction.
Part 3: You can change the interpretation of the triggers.
Part 4: Better interpretations lead to better reactions.
Part 2+3+4: It is better to set the hand brake than to try to stop a car rolling down the hill.
Part 5: Laughter is one of the best medicines. (laughter seems to help erase some of the negative learning that comes from heavy emotional situations and reduce physiological stress reactions)
Going from my memories of getting through that stage myself with a little psychology training thrown in there...
Work out a "situation review strategy" with him, but let it be his to implement on his own. This should be him relaxing in his own space and thinking through what led to a blow-up (depending on his style preference he may want to write down his thgouhts.) As he contemplates each item, he can work to identify what bothered him and what in his mind reacted poorly to the situation. Then he can look for other interpretations for the same situation that do not lead to the negative outcome.
I also would suggest him looking for a funny perspective on each trigger, as that is another vantage point where he can diffuse and take control of his reaction.
I'd suggest finding some basic meditation technique for him to relax into a mindset to do this type of exercise.
Some self-coaching questions to help in "rewriting" his emotional filters:
- What is really at stake here?
- What is the worse thing that can happen? Really??
- What will I gain by becoming angry at this? What will I lose?
- Is my reaction in scale with the situation?
- What is the honest/fair level of reaction I should have?
