Quiet Power: The Secret Strengths of Introverts

by Susan Cain

What do I mean by “reactivity to stimulation”? Well, most psychologists agree that introversion and extroversion are among the most important personality traits shaping human experience—and that this is true of people all over the world, regardless of their culture or the language they speak. This means that introversion is also one of the most researched personality traits. We’re learning fascinating things about it every day. We now know, for example, that introverts and extroverts generally have different nervous systems. Introverts’ nervous systems react more intensely than extroverts’ to social situations as well as to sensory experiences. Extroverts’ nervous systems don’t react as much, which means that they crave stimulation, such as brighter lights and louder sounds, to feel alive. When they’re not getting enough stimulation, they may start to feel bored and antsy. They naturally prefer a more gregarious, or chatty, style of socializing. They need to be around people, and they thrive on the energy of crowds. They’re more likely to crank up speakers, chase adrenaline-pumping adventures, or thrust their hands up and volunteer to go first.