Miina Matsuoka lives by herself in New York City. She owns two cats and routinely screens her calls. But before you jump to conclusions, note that she is comfortable hobnobbing in any of five languages for her job as business manager at an international lighting-design firm. She just strongly prefers not to socialize, opting instead for long baths, DVDs, and immersion in her art projects. She does have good, close friends, and goes dancing about once a month, but afterward feels a strong need to "hide and recoup." In our society, where make up three-quarters of the population, loners (except Henry David Thoreau) are pegged as creepy or pathetic. But soloists like Matsuoka can function just fine in the world—they simply prefer traveling through their own interior universe.

Loners often hear from well-meaning peers that they need to be more social, but the implication that they're merely black-and-white opposites of their bubbly peers misses the point. Introverts aren't just less sociable than extroverts; they also engage with the world in fundamentally different ways. While outgoing people savor the nuances of social interaction, loners tend to focus more on their own ideas—and on stimuli that don't register in the minds of others. Social engagement drains them, while quiet time gives them an energy boost.

Contrary to popular belief, not all loners have a pathological of social contact. "Some people simply have a low need for affiliation," says Jonathan Cheek, a psychologist at Wellesley College. "There's a big subdivision between the loner-by-preference and the enforced loner." Those who choose the living room over the ballroom may have inherited their temperament, Cheek says. Or a penchant for solitude could reflect a mix of innate tendencies and experiences such as not having many friends as a child or growing up in a family that values privacy.

James McGinty, for one, is a caseworker who opted out of a as a lawyer because he didn't feel socially on-the-ball enough for the job's daily demands. He has a small circle of friends, but prefers to dine solo. "I had a bad cold over the Thanksgiving holiday, but that spared me from having to go to my brother-in-law's," he says. "I'm not a scrooge; it's the gatherings I dread." Matsuoka feels his pain: "I can't do large crowds with a lot of noise," she says. "It's to maintain positive interactions and introduce yourself 20 times. I really have to turn on my motor to do that."

Solitary Pleasures

Matsuoka, who is , is open to , but "whomever I'm with must know that at least one day a week I need to lock myself in my room and stick feathers on a sculpture," she warns. Artwork is a form of for her. "I get completely sucked in. It clears my mind until nothing disturbs me." While a few studies have shown a correlation between , originality, and , perhaps more striking is the greater enjoyment introverts seem to reap from creative endeavors.

Amanda Guyer, a psychologist at the National Institutes of Health in Bethesda, Maryland, has found that socially withdrawn people have increased sensitivity to all kinds of emotional interactions and sensory cues, which may mean that they find pleasure where others do not. Guyer separated child subjects into "outgoing" and "reserved" groups and then had them play a game in which they had to press a button in order to win money. The reserved subjects showed two to three times more activity in the striatum region of the brain, which is associated with reward, than did the more outgoing ones.

Previous MRI studies have shown that during social situations, specific areas in the brains of loners experience especially lively blood flow, indicating a sort of overstimulation, which explains why they find parties so wearying. But Guyer's results suggest that introverts may be more attuned to all sorts of positive experiences as well. This added sensitivity, she speculates, could mean that people who are reserved have an ability to respond quickly to situations—such as coming to your aid in a moment of need—or show unusual to a friend, due to their strong emotional antennae.

Research by psychotherapist Elaine Aron bears out Guyer's hunch, demonstrating that withdrawn people typically have very high sensory acuity. Because loners are good at noticing subtleties that other people miss, Aron says, they are well-suited for careers that require close observation, like writing and scientific research. It's no surprise that famous historical loners include Emily Dickinson, Stanley Kubrick, and Isaac Newton.

The Unhealthy Case of the Lonely Loner

The content introverts' camp closely borders the land of the socially . Matsuoka, for example, says she was "pathologically shy" as a child, which likely laid the groundwork for her current lifestyle, even though she grew much more confident in her 20s. Those who remain "enforced loners" long to spend time with people, but and anxiety inhibit them from doing so. "Introverts are people who like to be alone," says Paula Montgomery, an accountant from St. Louis. "I prefer to be around other people, but because of my shyness, it's difficult for me to join groups and make friends."

Such loners have several stress-inducing strikes against them: They may get butterflies whenever they have to face in-person encounters, and they are subject to outside pressure to be sociable. When major life problems crop up, loners are also less likely to seek out social support.

John Cacioppo, a psychologist at the University of Chicago, has highlighted as a health-risk factor on par with and . "Loneliness is like hunger and thirst—a signal to help your survive," Cacioppo says. "When you're lonely, there's a stress response in your body, and it's not healthy to sustain that for a long time."