I'm not so sure high intelligence really protects you from reacting with emotions or act irrationally. Plenty of intelligent people can still react very emotionally or even irrationally. Though I suppose reacting intellectually has a higher pay-off for them than for most.

Having intelligence in most cases just means you're better at post-hoc justification of your emotionally-driven decisions.

Agreed, however those who arent intelligent repeat the same emotional responses over and over. Intelligence gives you the possibility of changing that, unintelligent dont have that possibility.