When do we start taking verbal effervescence

When do we start taking verbal effervescence, if not verbal diarrhea as a sure marker of intelligence?

As for leadership ability facilitated by one's willingness to speak up,in a classroom or beyond, well, maybe you can find a disastrous example in Hillary Clinton, among many others. Leadership is about personality, not ability. Leaders are a type of person who could not sit still, keep their mouths shut, or take care of their own life (including their own family life, again Hillary Clinton will be a good example). They are somehow self-persuaded that they have leadership "ability" and can take care of many others. Leaders they are, for sure, of fools, I must add.