Always Say Less Than Necessary: when you are trying to impress people with words, the more you say, the more common you appear, and the less in control. Even if you are saying something banal, it will seem original if you make it vague, open-ended, and sphinxlike. Powerful people impress and intimidate by saying less. The more you say, the more likely you are to say something foolish.
In my experience, intellectual capacity directly correlates to vocalization. It would appear that loud an aggressive people possess some defect in character and mental capacity. I believe the thoughtful quiet person, may possess finer qualities such as discipline and self-restraint. The silent runner perhaps travels faster and farther than another who heralds his or her own arrival.