Big companies are constantly looking for people to move across divisions or around the world, and extroverts appear more prepared for such opportunities.
With their charisma and superior verbal skills, they're thought to be more "out front," able to communicate powerfully and motivate their people, especially during tough times. Extroverts also tend to forge relationships with more ease, another boon in complex hierarchies. And finally, extroverts tend to outshine introverts because early on, their outsize personalities earn them chances to make presentations to higher-ups.
Over time, many introverts stagnate in large organizations. They can work hard and deliver to expectations or beyond, but they rarely get their due. Indeed, big companies are so tilted towards extroverts that introverts within them often experience a dynamic not unlike the one faced by many women and minorities. They have to constantly overdeliver just to stay even.
If you want to take charge of your career, you would be wise to get some executive coaching and sound mentoring advice. So get out there, mix, speak more often, and connect with both your team and others, deploying all the energy and personality you can muster. Ultimately, any and all candor you can bring to your public transformation will hold you in good stead.
Source: BusinessWeek, December 8, 2008