'20/20' Friday: What Makes People Happy?

Several studies also suggest marriages are happier without kids. Additionally, despite the high divorce rate in the United States, married people remain happier than single people, which explains why so many divorcees get remarried.

The Money Mirage and Living Purposefully

Theyer Willis, the author of "Navigating the Dark Side of Wealth" and heir to the enormous Georgia-Pacific Timber fortune, will testify to that fact. Raised in a life of leisure and privilege, Willis by her mid-30s found herself isolated and miserable with no sense of purpose.

"Having a fulfilling, meaningful life and being happy doesn't have to do with what we have," she said. "It has to do with how we live our lives."

Willis now counsels families that are very rich and very sad. One of the strongest messages she imparts to her clients: find meaningful work.

Though he is far from a millionaire, Sean Aiken can relate to that advice. He is on his way toward working 52 jobs in 52 weeks as part of a yearlong quest to find his bliss. On his Web site Aiken chronicles his rapidly growing resume, which includes everything from brew master, dairy farmer, and bungee-jumping instructor to exterminator, stock trader, and veterinarian.

Not What You Do, but Who You Do It With

Aiken's breadth of experience has instilled in him the third fundamental -- it's not what you do, it's who you do it with. "I have realized that you could have the best or worst job in the world, it is the people you work with that are going to make it a positive or negative work environment," he said.

Positive psychologists break down the work force into those with jobs, those with careers and those with callings. Those who follow their calling are happiest, but right behind them are those who use sheer will to turn a job into a calling.

"Positive Paul" Hintersteiner is a perfect example; he's happy, which is amazing when you consider he is a New York City cab driver. For 12 hours a day he fights some of the world's worst traffic with deals with some of the world's most stressed-out people. And yet he takes it upon himself to brighten the day of everyone he meets; he tells corny jokes and hands out thank-you cards asking passengers to remember his optimism when their days get rough.

Finding 'Flow'

If a positive outlook provides one level of happiness, the fifth fundamental takes you even higher. If you can find an activity you love, you can find "flow." Conceptualized by psychologist Mihaly Csikszentmihalyi in the 1970s and commonly referred to with terms such as "in the zone," or "in the groove," flow is that transcendent state when a person becomes so engaged and focused in their passion, they lose all sense of themselves. It could come from a million different activities -- knitting, teaching, surfing, singing, speed chess, speed walking, playing an instrument, or playing solitaire.

For Jonas Gerard, an abstract painter and sculptor based in Asheville, North Carolina, it comes with a brush, paint and canvas. "When I am experiencing flow, I am really not in charge, I am allowing the flow to come through me and I am allowing the energy to direct my life … all flow is about allowing this energy and right here in the studio it's creative energy. I call it Creative Energy with a capital C and capital E. Because it's a very spiritual experience. When that flows, when that is flowing I can't stop it."

Asheville was recently named the happiest place in America by journalist Eric Weiner in his novel "The Geography of Bliss." That may help Gerard attain a constant level of happiness, but he insists flow has nothing to do with external circumstances.

"I have had horrible tooth aches recently, I am redoing my whole mouth with all kinds of artificial teeth and the pain is horrible, and I come to my studio and the pain goes away, I forget about eating, I forget about sleeping, I forget about all things when I am in this, like you call, a flow," he said. Researchers have learned that flow can also be destructive; many chess masters have spiraled into despair after beating all challengers. But the most satisfying endeavors are those that benefit others.

Charlie Todd understands that kind of satisfaction. He finds flow and spreads joy by shocking complete strangers. "I try to do things that are pranks, but while often pranks are about humiliating someone, I try to do things that are about making people happy, making someone's day, giving someone an awesome story to tell."

Todd is the founder of a group called Improv Everywhere whose Mission Statement is to "cause scenes of chaos and joy in public places." They are a New York based comedy troupe devoted to staging elaborate stunts, or what Todd likes to call "missions." An annual Improv Everywhere Mission is their "No Pants Subway Ride" where every January several "agents" ride their subway in their underwear. They pretend not to know each other, and a few stops later, a man boards -- selling pants. Other subway missions included a fake marriage proposal, where Todd and his co-conspirators recruited random strangers on the subway to help pop the question, a surprise birthday party, and an annual haunted Halloween train.

Socializing = Joy

Improv Everywhere doesn't limit themselves to underground transit -- they use all of New York City as their stage; from taking over the window space in a large commercial building on Union Square Park to organizing a giant game of twister with 800 strangers on the lower Manhattan waterfront, Todd's troupe forces strangers to interact with themselves and their city in unexpected and comical ways.

"I just love that moment because something that is unusual might scare an individual, but when you commiserate with other people around and realize there are other people who are also experiencing this it becomes fun and funny." It may seem silly or frivolous, but it represents the sixth and final fundamental, as summed up by Gilbert; "If you could only know one thing to understand human beings it would be this; human beings are social animals. Almost every one of our greatest sources of joy is a social source of joy, something about our interaction with or relationship with another person."