Quiet by Susan Cain

Introversion is a preference for environments with lower levels of stimulation. Between 30% and 50% of people are considered introverts, though the border is blurry because introversion and extroversion span a wide spectrum. Introversion is often confused with quietness, shyness, and sensitivity; these behaviors are correlated with introversion but are not an intrinsic part of the trait.

Compared to extroverts, introverts have higher sensory processing sensitivity and are more easily overwhelmed. Introverted brains have low sensitivity to rewards and high sensitivity to threats, creating personalities that are vigilant, diligent, and conscientious. Whereas the extrovert mindset is good at taking bold risks and winning big during times of opportunity, the introvert mindset is optimized for limiting risks and capping losses during times of hardship. Since introversion and extroversion are each effective in some environments but not in others, natural selection has not overwhelmingly chosen one trait over the other; both sides of the trait exist today. Introverts and extroverts can make effective pairings when placed together, with introverts counteracting extroverts’ uncalculated risk-taking and extroverts counteracting introverts’ aversion to action.

Modern western culture heavily favors extroversion over introversion, viewing extroversion as an ideal and introversion as an impairment. A preference for extroversion is not universal across all cultures and time periods; in America’s case, it arose during the country’s industrialization and urbanization. In the anonymous and crowded world of city life, it is advantageous to have good charisma, to be able to seize the spotlight, and to be able to promote yourself with style. In the new extroverted culture, introverts were repeatedly urged to “come out of their shell” and be more gregarious, bold, and energetic. On the flip side, since extroversion was considered normal, extroverts did not get balancing advice telling them to be more contemplative and mellow. With introverts viewing their personality as a disability, they were faced with the unpleasant choice of either pretending to be extroverts or letting themselves struggle in the rat race. The adoption of extrovert-centric culture coincided with the rise of the self-help industry and the rise of “social anxiety” as a diagnosis.

Even though group brainstorming and open office plans have repeatedly been demonstrated to be ineffective, these extrovert-friendly arrangements are still commonplace today. Schools put a huge focus on group work and collaborative activities at the expense of independent focus work, leaving introverted children constantly frazzled and out of their natural element. In group and team discussions, introverts often fade into the sidelines, unsure of their role on the team and fearful of saying something stupid.

Society ignores introverts to its own detriment. Introverts have many often-underappreciated strengths that come bundled with their trait. They have strong passions and thoughtful ideas but are often hesitant to talk much about them unless they feel they are in a socially safe environment. Introverts are disproportionately represented amongst high achievers in a wide variety of disciplines, especially those that require lots of grit and solo practice. Their unassuming personalities don’t antagonize other people and lend themselves nicely to beneficial cooperation. Thanks to their aversions to risk and insistence on thinking before acting, introverts are good at avoiding impulsive decisions.

To thrive in life, introverts should seek out environments that are supportive and roles that play to their natural strengths. However, introverts must also be willing to occasionally face their fears and experience novelty. It is perfectly normal and healthy for introverts to intentionally act out of character and behave like extroverts from time to time. For maximum benefit with minimized burnout risk, such episodes should be temporary, be sandwiched between restorative periods, and be done only in the pursuit of genuinely meaningful goals.