Quiet: The Power of Introverts in a World That Can't Stop Talking

by Susan Cain

When you practice deliberately, you identify the tasks or knowledge that are just out of your reach, strive to upgrade your performance, monitor your progress, and revise accordingly.

In fact, some scientists are starting to explore the idea that reward-sensitivity is not only an interesting feature of extroversion; it is what makes an extrovert an extrovert. Extroverts, in other words, are characterized by their tendency to seek rewards, from top dog status to sexual highs to cold cash. They’ve been found to have greater economic, political, and hedonistic ambitions than introverts; even their sociability is a function of reward-sensitivity, according to this view—extroverts socialize because human connection is inherently gratifying.

By contrast, introverts “have a smaller response” in the reward system, writes psychologist Nettle, “and so go less out of their way to follow up [reward] cues.” They will, “like anyone, be drawn from time to time to sex, and parties, and status, but the kick they get will be relatively small, so they are not going to break a leg to get there.” In short, introverts just don’t buzz as easily.