During a Lord of the Flies discussion, my sophomore English class agreed unanimously (I being the lone dissenter) that extroverts are inherently better leaders than introverts, and it's a commonly held perception in our aggressive "fight for what you want" society. However, I've never believed it, and neither does Susan Cain. Backed up by scientific studies and statistical evidence as well as various anecdotes, this book annihilates that assumption with a qualified thesis - introverts and extroverts can be equally effective leaders; they shine in different situations - that lends its assertions additional credibility.

That said, it's not the most engaging read; in some parts it's downright repetitive. Overall though, it addresses an important and relevant topic, and it's worth reading at least once.