Is introversion a prerequisite to creativity?

Just in case any of you believe that writing a decent blog post weekly is easy, allow me to dispel this notion.  When I have an idea brewing or an obvious story to tell, it is less difficult.  When I’m emotionally unsettled or my subconscious is working through something, it rises to the surface of the page pretty quickly.
The writer’s block emerges when I’m happy.  When I feel balanced and social and engaged with my job and friendships, and rummage around my heart and mind for an idea, I find nothing but stale air. It’s as if my muse (the little bitch) is trying to punish me for abandoning her.
When I was writing my novel, I sentenced myself to solitary confinement. Solitude breeds creativity, and while those dark evenings were somber and lonely (my “emotional playlist” of 100 sad sad songs didn’t help), I was able to connect to my inner voice – my inner life.  It was a tough choice to say no to socializing, and yes to putting words on a page, but it was never a question of whether I should.
I enjoyed this time, and crave it too. My mother says I was like this as a child, evidenced by Super-8 films (yes, it was a long time ago) of birthday parties (my own) where I’d be playing quietly in a corner alone, away from my chatty little friends.  I am the middle child, the black sheep if you will, and had always considered myself an introvert.
There was a wonderful article in the NYT a few weeks ago http://www.nytimes.com/2011/06/26/opinion/sunday/26shyness.html?_r=1 about shyness and whether introversion is an evolutionary tactic, but mostly it outlines the differences between extroverts (“rovers”) and introverts (“sitters”).  “….many of the most creative people in a range of fields are introverts who are comfortable working in solitary conditions in which they can focus attention inward. Steve Wozniak, the engineer who founded Apple with Steve Jobs….describes his creative process as an exercise in solitude. “Most inventors and engineers I’ve met are like me… they’re shy and they live in their heads. They’re almost like artists. In fact, the very best of them are artists. And artists work best alone.”
For anyone who has undergone the writing process, the above is not a revelation. It is a prerequisite.
So it’s not a wonder that the writer in me is coming up blank lately. I don’t think I’m ignoring my emotions, but I am decidedly (and happily) in extrovert mode. My new job has brought it out in me. The introvert in me would have never thought I’d work in sales, be decent at it, let alone enjoy it. But in the last few months, and especially the last two weeks, I’ve been meeting many interesting people, forging new friendships, and planning events.
And loving it.
But then where does the writing mindset, the drive to sit down alone and write, fit in? Do we have to be reclusive, or emotionally off kilter, to be able to write? Or write well? Can one be both an extrovert and an introvert, and manage to excel and find fulfillment in both spaces?
I’m guessing it all comes down to the yin and yang of life. Because if you’re not a curious person, curious about the world, people, or ideas – and you don’t seek to explore what makes it all tick or to connect with others – then what in the world would you have to write about?