According to the book 'Quiet: The Power of Introverts in a World That Can't Stop Talking' by Susan Cain, about 30-50% of the population are introverts.
I am an Introvert. That will surprise many people who know me. Although I am very comfortable in social situations, and I love being around people, I need time alone to think and be by myself. I really loved the book and I highly recommend it. It gave me great insight into myself and other people that I know.
A myth that Dan Pink, author of To Sell Is Human writes is that extroverts make the best salespeople. No research backs that up. He offers a free assessment to determine if you are an introvert, extrovert, or what he calls an ambivert. An ambivert is the middle ground of the assessment where most people fall.
I completed the free assessment and my results are below:
You're an ambivert. That means you're neither strongly introverted nor strongly extraverted. Recent research by Adam Grant of the University of Pennsylvania's Wharton School of Management has found that ambiverts make the best salespeople. Ambiverts tend to be adept at the quality of attunement. They know when to push and when to hold back, when to speak up and when to shut up. So don't fall for the myth of the extraverted sales star. Just keep being your ambiverted self.
AMAZON DESCRIPTION of Quiet:
At least one-third of the people we know are introverts. They are the ones who prefer listening to speaking, reading to partying; who innovate and create but dislike self-promotion; who favor working on their own over brainstorming in teams. Although they are often labeled "quiet," it is to introverts that we owe many of the great contributions to society--from van Gogh’s sunflowers to the invention of the personal computer.
Passionately argued, impressively researched, and filled with indelible stories of real people, Quiet shows how dramatically we undervalue introverts, and how much we lose in doing so. Taking the reader on a journey from Dale Carnegie’s birthplace to Harvard Business School, from a Tony Robbins seminar to an evangelical megachurch, Susan Cain charts the rise of the Extrovert Ideal in the twentieth century and explores its far-reaching effects. She talks to Asian-American students who feel alienated from the brash, backslapping atmosphere of American schools. She questions the dominant values of American business culture, where forced collaboration can stand in the way of innovation, and where the leadership potential of introverts is often overlooked. And she draws on cutting-edge research in psychology and neuroscience to reveal the surprising differences between extroverts and introverts.
Perhaps most inspiring, she introduces us to successful introverts--from a witty, high-octane public speaker who recharges in solitude after his talks, to a record-breaking salesman who quietly taps into the power of questions. Finally, she offers invaluable advice on everything from how to better negotiate differences in introvert-extrovert relationships to how to empower an introverted child to when it makes sense to be a "pretend extrovert."
This extraordinary book has the power to permanently change how we see introverts and, equally important, how introverts see themselves.