Susan Cain, author of Quiet: The Power of Introverts in a World That Can’t Stop Talking sticks up for introverts in her TED talk:

Overall, I doubt there’s a clear “better” between introverts and extroverts. They both have strengths and weaknesses, which we’re learning more about every day.

Here are a few more interesting tidbits:

1. You can generally trust your gut when trying to determine how introverted/extroverted someone is. Faces, handshakes and Facebook profiles are all accurate predictors.
2. Taste in music is predictive of personality. Enjoy upbeat and conventional tunes? You’re probably an extrovert.
3. Dog person or cat person? Dog people are 15% more extroverted.
4. Are you a morning person? They’re often introverts.
5. Extraversion and introversion predict what sex acts people are interested in.