Summary

The author begins the book with the story of Rosa Parks, who, with a single word--"no"--ignited the Montgomery Bus Boycott of 1955-56 and the Civil Rights movement. An African-American seamstress, Parks quietly refused to get out of her seat in the white section of a bus in Montgomery, Alabama, and was arrested. The result was a protest led by Martin Luther King. When Parks died in 2005, she was roundly praised as quiet and soft-spoken. Parks herself was aware of the paradox of her quiet and forceful nature and had called her autobiography "Quiet Strength."

The author notes that in addition to being affected by race and gender, our lives are affected by the most important aspect of personality--what one scientist refers to as "the north and south of temperament"--whether we are introverts or extroverts. This dimension of personality affects the degree...