Quiet is an excellent read for anyone who is introverted themselves or who knows someone who is (which is virtually everyone, according to Cain 1/3 people are). The book has excellent research and numerous sources.
Susan Cain draws from a variety of scientific articles and personal anecdotes to present why introversion is undervalued in Western society. As a life-long introvert myself, it’s comforting to hear the similar struggles of Cain and other introverts. She describes the historical journey in America toward achieving what she calls the “extrovert ideal.” The “extrovert ideal” values gregarious, go-getters with lots of energy and who are always on the move. Introverts are ignored or passed over because of this ideal. This doesn’t happen because their ideas are less valuable, but because they are reserved. In order to not be passed over, introverts often take on the characteristics of extroverts. Cain uses herself as an example as someone who must act extroverted for her work. She also uses historically relevant figures such as Rosa Parks, who dreaded the spotlight but was still a symbol of quiet strength. She uses everyday introverted stories from church leaders and students; there are people from all walks of life included.
She talks about the information in the book in a discussion for TED talks.
I would recommend Quiet to people who enjoy psychological non-fiction and understanding how people interact with each other. It’s especially great for anyone in the business world.