In the first study, Grant and his colleagues analyzed data from one of the five biggest pizza chains in the United States. They discovered that the weekly profits of the stores managed by extroverts were 16 percent higher than the profits of those led by introverts—but only when the employees were passive types who tended to do their job without exercising initiative. Introverted leaders had the exact opposite results. When they worked with employees who actively tried to improve work procedures, their stores outperformed those led by extroverts by more than 14 percent.

When you go to a football game and someone offers you a beer [...], they're really saying hi, have a glass of extroversion.

Every American was to become a performing self.

Even when the attention focused on me is positive, I am uncomfortable being looked at by a lot of people - it's just not my natural state of being.

Remember that introverts react not only to new people, but also to new places and events. So don’t mistake a child’s caution in new situations for an inability to relate to others. He’s recoiling from novelty or overstimulation, not from human contact. Introverts are just as likely as the next kid to seek others’ company, though often in smaller doses

I use a lot of old-fashioned expressions.

Many Introverts are also "highly sensitive," which sounds poetic, but is actually a technical term in psychology. If you are a sensitive sort, then you're more apt than the average person to feel pleasantly overwhelmed by Beethoven's "Moonlight Sonata" or a well-turned phrase or an act of extraordinary kindness. You may be quicker than others to feel sickened by violence and ugliness, and you likely have a very strong conscience.