Four Kinds of Introversion

Social: Social introversion is the closest to the commonly held understanding of introversion, in that it's a preference for socializing with small groups instead of large ones. Or sometimes, it's a preference for no group at all — solitude is often preferable for those who score high in social introversion. "They prefer to stay home with a book or a computer, or to stick to small gatherings with close friends, as opposed to attending large parties with many strangers," Cheek said. But it's different from shyness, in that there's no anxiety driving the preference for solitude or small groups.

Thinking: Thinking introversion is a newer concept. People with high levels of thinking introversion don't share the aversion to social events people usually associate with introversion. Instead, they're introspective, thoughtful, and self-reflective. "You're capable of getting lost in an internal fantasy world," Cheek said. "But it's not in a neurotic way, it's in an imaginative and creative way." Think the dreamily imaginative Luna Lovegood, not the socially awkward Neville Longbottom, Cheek said, putting it into Harry Potter terms I, for one, am deeply familiar with.

Anxious: Unlike social introverts, anxious introverts may seek out solitude because they feel awkward and painfully self-conscious around other people, because they're not very confident in their own social skills. But, often, their anxiety doesn't fade when they're all alone. This kind of introversion is defined by a tendency to ruminate, to turn over and over in their minds the things that might or could or already have gone terribly wrong.

Restrained: Another word for this one is reserved. Restrained introverts sometimes seem to operate at a slightly slower pace, preferring to think before they speak or act. They also might take a while to get going — they can't, for instance, wake up and immediately spring into action. Haruki Murakami's What I Talk About When I Talk About Running contains a passage that I think neatly illustrates the restrained introverts, when he discusses how it takes his muscles a while to warm up when he starts to run. "When I put on my jogging shoes in the morning and set out, my feet are so heavy it feels like I'll never get them moving," he writes. He says it's the way his mind works, too: slow to get going. Murakami, I would bet, is a restrained introvert.

- So Apparently There Are 4 Kinds of Introversion