Apologies for the long review, but I believe this book merits a lot of discussion.
I discovered 'Quiet' by Susan Cain when, in frustration after being criticised for not having a great aptitude for making small talk with strangers, I googled the word 'introvert'. I know myself well enough to know that my lack of small-talking skills in busy environments or large groups is essentially hardwired into my brain, and I wanted to know if there was anyone who could empathise with this or if I was simply an aberration. Fortunately I found 'Quiet', and it's been one of the most helpful, timely and affirming books I've ever possessed.
'Quiet' not only gives insight into the neurological makeup of introverts, but also includes a lot of helpful information about how an introvert can make the most of his or her way of thinking. For example, Cain points out that the brain chemistry of extroverts makes them reward-driven, while introverts are far less so. So she suggests that when it comes to a career, introverts need to 'find their flow' - that is, an activity that can make them feel rewarded solely by the process of immersing themselves in their work, rather than by the 'reward' pay-off sensation that often drives extroverts to achieve.
Cain is enough of a realist to understand that there are many situations in life where introverts necessarily have to act extroverted, which can put introverts in a dilemma because it may seem as if we're being deceptive or disguising our true selves to the detriment of our emotional wellbeing. However, acting extroverted can be justified, Cain suggests, in pursuit of achieving the goals of our 'core personal projects': if you find something you care about enough, you can choose to find the willpower to appear extroverted where necessary in order to achieve it. I have found this to be a very helpful principle that I can use to determine when and where to put on my 'extrovert' face.
I'd recommend 'Quiet' to anyone who is introverted or highly sensitive, anyone who is in a position of leadership of any kind, and anyone who is in any sort of relationship with someone who is perplexingly reclusive or quiet. If you are an introvert, reading 'Quiet' may give you the affirmation you rarely receive in a world that fixates on 'bringing you out of your shell'. In fact, reading it may give you enough self-acceptance to repair the damage done by the social exclusion/stigmatisation that introversion can bring, and make you a lot more confident in social situations. I work in a busy environment surrounded by people constantly competing for my attention, but since reading 'Quiet' I have found that not only do I no longer feel bad about finding my work environment hard to handle, but I can also actually handle its demands so much more easily.
One final note: Cain has been criticised for mixing up her labels - sometimes she seems to be describing introverts; other times, the highly sensitive. However, this isn't such a big problem when you consider that the premise of 'Quiet' is essentially that silence, thoughtfulness, seriousness and a propensity for solitude are underrated in our culture, and that people who embody these characteristics tend to be either introverted or highly sensitive or both. Moreover, there is a huge overlap between introversion and high sensitivity. Cain adresses this issue in a note at the back of her book, and it seems clear to me that her purpose isn't to label people or cause us to label ourselves, but to make us all more aware and respectful of the different values embodied by different people.