Quiet: The Power of Introverts in a World That Can't Stop Talking is a 2012 nonfiction book written by American author and speaker Susan Cain.

Cain argues that modern Western culture misunderstands and undervalues the traits and capabilities of introverted people, leading to "a colossal waste of talent, energy, and happiness.

Adopting scientific definitions of introversion and extroversion as preferences for different levels of stimulation, Quiet outlines the advantages and disadvantages of each temperament, emphasizing the myth of the extrovert ideal that has dominated in the West since the early twentieth century.

Asserting that temperament is a core element of human identity, Cain cites research in biology, psychology, neuroscience and evolution to demonstrate that introversion is both common and normal, noting that many of humankind's most creative individuals and distinguished leaders were introverts.

[4] Her interest in writing on the subject of introversion reportedly stemmed from her own difficulties with public speaking, which made Harvard Law School "a trial".

[5] Seven years in the making,[4] Cain's book, Quiet: The Power of Introverts in a World That Can't Stop Talking was published January 24, 2012.

[7] Asked what inspired her to write the book, Cain likened introverts today to women at the dawn of the feminist movement—second-class citizens with gigantic amounts of untapped talent.

[6][11][13][14] The Globe and Mail's Zosia Bielski described this transformation as being aligned with "the rise of the salesman" and "the move from morals to magnetism"—which Cain says has changed forever "who we are and whom we admire, how we act at job interviews and what we look for in an employee, how we court our mates and raise our children".

[10] Cain says collective thinking approaches not only favor dominant extroverts,[16] but that relying on brainstorming is a mistake, arguing that serious original thought and the expertise that generates it are almost always individual.

[25] Cain's research included visits to what she termed three nerve centers of the Extrovert Ideal—a Tony Robbins self-help seminar, the Harvard Business School, and a megachurch—noting the discomfort and struggles experienced by introverts in those environments[23] and "shining a light" on the bias against introversion.

"[20] However, Cain essentially adopts the "Free Trait Theory" of Dr. Brian Little, agreeing that introverts are capable of acting like extroverts for (core personal goals[17])—work they consider important, people they love, or anything they value highly[27]—provided they also grant themselves restorative niches, which are places to go and time to be their real selves.

[23] Cain urges changes to the workplace to make it less focused on what she terms "The New Groupthink"—the idea that creativity and productivity emerge from a necessarily gregarious place—and more conducive to deep thought and solo reflection.

[1] According to Cain, research shows that charismatic leaders earn bigger paychecks but do not have better corporate performance; that brainstorming results in lower quality ideas and the more vocally assertive extroverts are the most likely to be heard; that the amount of space allotted to each employee has shrunk 60% since the 1970s; and that open office plans are associated with reduced concentration and productivity, impaired memory, higher turnover and increased illness.

[15] Cain describes how introversion in children is not a defect but instead may involve a careful, sensitive temperament that may bring stronger academics, enhanced creativity and a unique brand of leadership and empathy.

Cain says that introverts win a disproportionate number of Phi Beta Kappa keys and National Merit Scholarship finalist positions, cheat and break rules less, are more likely to be described by parents and caregivers as empathetic or conscientious, and are less likely to get into car accidents, participate in extreme sports and place large financial bets.

[5] Cain is not seeking introvert domination but a better balance and inclusion of different work styles, acknowledging that big ideas and great leadership can come from either personality type.

[10] The Harvard Independent's Faith Zhang closed her review of Quiet with the observation that Cain's point is not that introverts are inherently superior or that we should all shroud ourselves in solitude, but that diversity provides balance and makes for a fuller, richer world.

[25] She adds that we're at the cusp of a real sea change in the way we understand this personality type,[25] Cain's own website urging readers to "join the Quiet Revolution".

[38] Within one week of its publication, Forbes' Jenna Goudreau noted that the book was featured by several major media outlets and was shared extensively across the Web.

[25] Within three weeks of publication, InformationWeek's Debra Donston-Miller noted that introversion and extroversion were being widely discussed due in large part to Quiet,[39] Cain's work being the focus of Time magazine's February 6, 2012 cover article.

[17] In 2015, Laura Holson wrote in The New York Times that Cain had "started, or at least was on the forefront of, a bona fide publishing trend" concerning introverts,[36] and in 2017 Harvard Magazine's Lydialyle Gibson noted that in the aftermath of Quiet, "introversion came suddenly into vogue".

[44] Changes caused by Quiet include Steelcase collaborating with Cain (2014) to design office spaces to include quiet areas where workers can have privacy for a time, in contrast to open plan offices,[45] and Herman Miller matching work models (e.g., impromptu chats, team status-report huddles, and concentrated individual work) with physical settings (e.g., bench desk, small meeting room, open forum).

"[51] Cornell Law School's Sherry Colb extended to the jury system Quiet's assertion that a successful "wisdom-of-crowds phenomenon" typically emerges when individuals in a group share their respective contributions after being separately and independently conceived.

[52][53] Quiet's critiques of groupwork and brainstorming were cited in the writings of such sources as Harvard Business School's Professor Emeritus James Heskett[54] and Fast Company's Co.Design senior editor Belinda Lanks.

[59] DiSalvo cited studies indicating that introverts' elevated sensitivity to personality traits can manifest as bias against extroverts in performance appraisals and reward giving.

[5] Warner also stated that Cain "combines on-the-scenes reporting with a wide range of social science research and a fair bit of 'quiet power' cheerleading".