They find their most golden self. Picture happiness. What do you see? A peaceful soul sitting in a field of daisies appreciating the moment? That kind of passive, pleasure-oriented—hedonic—contentment is definitely a component of overall happiness. But researchers now believe that eudaimonic well-being may be more important. Cobbled from the Greek eu ("good") and daimon ("spirit" or "deity"), eudaimonia means striving toward excellence based on one's unique talents and potential—Aristotle considered it to be the noblest goal in life. In his time, the Greeks believed that each child was blessed at birth with a personal daimon embodying the highest possible expression of his or her nature. One way they envisioned the daimon was as a golden figurine that would be revealed by cracking away an outer layer of cheap pottery (the person's base exterior). The effort to know and realize one's most golden self—"personal growth," in today's lingo—is now the central concept of eudaimonia, which has also come to include continually taking on new challenges and fulfilling one's sense of purpose in life.

"Eudaimonic well-being is much more robust and satisfying than hedonic happiness, and it engages different parts of the brain," says Richard J. Davidson, PhD, of the University of Wisconsin-Madison. "The positive emotion accompanying thoughts that are directed toward meaningful goals is one of the most enduring components of well-being." Eudaimonia is also good for the body. Women who scored high on psychological tests for it (they were purposefully engaged in life, pursued self-development) weighed less, slept better, and had fewer stress hormones and markers for heart disease than others—including those reporting hedonic happiness—according to a study led by Carol Ryff, PhD, a professor of psychology at the University of Wisconsin-Madison.

They design their lives to bring in joy. It may seem obvious, but "people don't devote enough time to thinking seriously about how they spend their life and how much of it they actually enjoy," says David Schkade, PhD, a psychologist and professor of management at the University of California, San Diego. In a recent study, Schkade and colleagues asked more than 900 working women to write down everything they'd done the day before. Afterward, they reviewed their diaries and evaluated how they felt at each point. When the women saw how much time they spent on activities they didn't like, "some people had tears in their eyes," Schkade says. "They didn't realize their happiness was something they could design and have control over."

Analyzing one's life isn't necessarily easy and may require questioning long-held assumptions. A high-powered career might, in fact, turn out to be unfulfilling; a committed relationship once longed for could end up being irritating with all the compromising that comes with having a partner. Dreams can be hard to abandon, even when they've turned sour.

Fortunately, changes don't have to be big ones to tip the joy in your favor. Schkade says that if you transfer even an hour of your day from an activity you hate (commuting, scrubbing the bathroom) to one you like (reading, spending time with friends), you should see a significant improvement in your overall happiness. Taking action is key. Another recent study, at the University of Missouri, compared college students who made intentional changes (joining a club, upgrading their study habits) with others who passively experienced positive turns in their circumstances (receiving a scholarship, being relieved of a bad roommate). All the students were happier in the short term, but only the group who made deliberate changes stayed that way.

They avoid "if only" fantasies.  If only I get a better job…find a man…lose the weight…life will be perfect. Happy people don't buy into this kind of thinking.

The latest research shows that we're surprisingly bad at predicting what will make us happy. People also tend to misjudge their contentment when zeroing in on a single aspect of their lives—it's called the focusing illusion. In one study, single subjects were asked, "How happy are you with your life in general?" and "How many dates did you have last month?" When the dating question was asked first, their romantic lives weighed more heavily into how they rated their overall happiness than when the questions were reversed.

The other argument against "if only" fantasies has to do with "hedonic adaptation"—the brain's natural dimming effect, which guarantees that a new house won't generate the same pleasure a year after its purchase and the thrill of having a boyfriend will ebb as you get used to being part of a couple. Happy people are wise to this, which is why they keep their lives full of novelty, even if it's just trying a new activity (diving, yoga) or putting a new spin on an old favorite (kundalini instead of vinyasa).

They put best friends first. It's no surprise that social engagement is one of the most important contributors to happiness. What's news is that the nature of the relationship counts. Compared with dashing around chatting with acquaintances, you get more joy from spending longer periods of time with a close friend, according to research by Meliksah Demir, PhD, assistant professor of psychology at Northern Arizona University. And the best-friend benefit doesn't necessarily come from delving into heavy discussions. One of the most essential pleasures of close friendship, Demir found, is simple companionship, "just hanging out," as he says, hitting the mall or going to the movies together and eating popcorn in the dark

They allow themselves to be happy. As much as we all think we want it, many of us are convinced, deep down, that it's wrong to be happy (or too happy). Whether the belief comes from religion, culture, or the family you were raised in, it usually leaves you feeling guilty if you're having fun.

"Some people would say you shouldn't strive for personal happiness until you've taken care of everyone in the world who is starving or doesn't have adequate medical care," says Howard Cutler, MD, who co-authored The Art of Happiness in a Troubled World with the Dalai Lama. "The Dalai Lama believes you should pursue both simultaneously. For one thing, there is clear research showing that happy people tend to be more open to helping others. They also make better spouses and parents." And in one famous study, nuns whose autobiographies expressed positive emotions (such as gratitude and optimism) lived seven to 10-and-a-half years longer than other nuns. So, for any die-hard pessimist who still needs persuading, just think of how much more you can help the world if you allow a little happiness into your life.

Gabrielle LeBlanc is a writer and neuroscientist in Washington, D.C.

By Gabrielle LeBlanc from O, The Oprah Magazine, March 2008 © 2008 Harpo Productions, Inc. All Rights Reserved