For as little as these locations have in common, they share one delightful trait: Their residents rate among the happiest in the world. Find out what they know, and what they can teach the rest of us, about living well.

When National Geographic sent explorer and journalist Dan Buettner abroad in 2007 to research the secrets of the world’s longest-lived societies, he interviewed one scrappy centenarian from the seat of her exercise bike. Another beat him at arm wrestling. The citizens of what Buettner subsequently called the globe’s “Blue Zones” not only demonstrated an unusual capacity for longevity, they also displayed an extraordinarily positive outlook and zest for life.

In his first best-selling book, The Blue Zones: Lessons for Living Longer from the People Who’ve Lived the Longest (National Geographic, 2008), Buettner touched on the intrinsic role this sort of joie de vivre seemed to have on longevity. Then he decided to dig deeper and make an exploration of the world’s “happiness hot spots” the central focus of his newest book, Thrive: Finding Happiness the Blue Zones Way (National Geographic, 2010).

Thanks to a decade-worth of surveys measuring well-being on a global scale, National Geographic researchers already knew where these hots spots were located. Buettner’s investigative mission: finding out what accounted for the happy lots of these residents, and how the rest of us could leverage some of their central lessons on satisfaction — regardless of where we live.

Apparently, longitude and latitude aren’t the deciding factors. The locales Buettner investigated (Denmark, Singapore, northeastern Mexico and San Luis Obispo, Calif.) are notably diverse, geographically and culturally.

Each society faces different but daunting inherent challenges, like months of winter darkness, prohibitive property costs or rampant police corruption. Still, they share a sense of well-being that comes mostly from ordinary, daily routines and rituals (many involving friends and family), combined with a collective quality of life — one not tied to individual surpluses of money or professional power.

We often mistakenly try to measure happiness by life’s high points, Buettner says, yet the hot spots suggest that “lived happiness” usually derives from mundane, repeated acts and moments too ordinary to attract notice. Like regularly walking to the store instead of driving. Like enjoying your work. Like feeling safe on the street at night.

Buettner’s hope is that by better understanding the everyday habits and attitudes of happy people around the world, we’ll all stand a better chance at becoming happier ourselves. We can stop looking for happiness in all the wrong places, and put our energy to more worthwhile and rewarding uses instead.

Here’s just a little of what Buettner learned, and what he’d like us all to know, about the four happiest places on Earth.

1. Denmark

Cloaked in almost total darkness during the winter months, Denmark nonetheless rates second in the World Database for Happiness. Known for its egalitarian principles and strong social safety net, Denmark has a very high tax rate.

Danes aren’t particularly bothered by this, Buettner discovered, because they are satisfied with the way their taxes are spent, and they don’t have the same attachment to “getting ahead” felt so keenly by many Americans. “The Danish path to happiness isn’t about aspiring to scale peaks,” Buettner explains, “but rather about the satisfaction that comes from living on a high plateau.”

Take the example of Jan Hammer, a garbage collector in Denmark’s second-largest city, Århus. Hammer is married and the father of three girls. On his annual salary of $80,000, he drives a Mercedes and takes his family to Greece each year. What’s more, he works only 21 hours a week, and after going to the gym and spa provided by his union, he arrives home by 3 p.m. every day. He helps his daughters with their homework after school and coaches their soccer team three nights a week. His life, by Buettner’s description, is “rewarding and full.”

Hammer takes pride in his profession. “You can’t find a better job than delivering garbage,” he tells Buettner on an early-morning ride through the alleys of Århus. The hours are excellent, he says. The high rate of pay matches that of a Danish lawyer, and there’s no social stigma attached to the vocation.

Thanks to their tax base, Denmark’s vast middle class is able to rely on a range of public services. Public funds guarantee everything from support for the elderly to paychecks for university students, so people’s incomes don’t get gobbled up by medical costs or educational debts.

As a result, people don’t overwork. The average Danish worker puts in 37 hours a week, takes six weeks of vacation, and has plenty of time left over for socializing and hobbies.

Lesson from Denmark: Cultivate Quality Time

Buettner points out that while Denmark’s tax strategy isn’t particularly transferable, its people’s lack of interest in excessive wealth might be.

More income, as it turns out, doesn’t always mean a better life. Buettner cites a study showing that Americans have increased their average income by 20 percent in the last 35 years, and doubled the size of their homes since 1950, yet on the whole, our nation is no happier.

“On a nationwide average, after about $75,000 for a U.S. family of four, more income doesn’t enable you to experience more happiness,” Buettner says. Once the necessities are covered, time is best spent doing the things most likely to cultivate authentic happiness, like visiting with friends or working in the garden. Experiences are more reliable satisfaction enhancers than new gadgets, he explains, since the “hedonistic effect” of goods tends to wear off quickly.

Overall happiness is largely due to balanced schedules and varied social activities.

Buettner’s Danish sources agree that their overall happiness is largely due to balanced schedules and varied social activities. Nineteen out of 20 Danes belong to some kind of club. And all that social interaction has a profound happiness-inducing effect. On average, according to Buettner, “Joining a club that requires you to show up once a month has the same impact on your happiness as a doubling of your income.”

2. Singapore

In stark contrast to Denmark, Buettner describes Singapore as “a society of workaholics.” In addition, its government is notorious for draconian security measures, and laws that prohibit gum chewing and spitting on the street. Yet recent studies measure higher levels of happiness in this city-state than anywhere else in Asia.

In Singapore, Buettner interviews a CEO of a major hotel chain. Like most well-heeled Singaporeans, Jennie Chua is also a model of philanthropy, sitting on the boards of 20 educational, charitable and business organizations. Born and raised in a small fishing village, she accrued her education and wealth through diligence and discipline. Buettner compares Chua’s story to the history of modern Singapore, which built its economy from scratch after gaining independence from the British in 1965.

Chua names five things she likes about life in Singapore: The streets are clean, women can walk anywhere at night safely, subways are always on time, public toilets have hand soap, and police are quick to help. When asked what is most important in her life, she points to a photograph of her two sons with their wives and children.

“For so long, it was such a struggle to put a roof over our heads,” she says. “Today we have more things, but our values are the same.”

For Chua and other Singaporeans, material gains matter most in their capacity to improve family and community life. There are government policies that reflect these values, like a subsidy for families who take in aging parents; 84 percent of Singaporean seniors live with their adult children.

Many also say the government’s harsh security tactics are the price they pay for a welcome feeling of public safety, no small feat when there are 5 million ethnically diverse citizens crowded onto one small island.

Lesson from Singapore: Give Security Its Due

Although Americans tend to prioritize freedoms, when it comes to creating a sense of satisfaction, it’s worth noting that security has an important role to play, too. “Maximizing freedom does not necessarily maximize collective happiness,” Buettner observes. “Unless we feel safe and secure, we can’t pursue the other aspects of living that give rise to genuine happiness: family, relationships and spiritual groundedness.”

Buettner suggests one easy way to translate the Singaporean security lesson into an American context: Take responsibility for solidifying your financial security. “Pay down your mortgage and pay off your car loan,” he recommends. The short-term thrill of making freewheeling purchases is unlikely to produce as much authentic happiness as a sense of long-term financial security.

3. Nuevo León, Mexico

This arid desert state in northeastern Mexico is better known for border-crossing heartbreak than happiness. Yet according to the World Values Survey, almost 60 percent of residents rate themselves as “very happy.” In fact, Mexico itself ranks second for overall happiness in the World Values Survey, which polled citizens from 1981 to 2007. The United States ranks 16th.

Buettner conducted an informal survey among the residents of Santa Catarina, a working-class neighborhood in the state’s capital of Monterrey. He found few who were surprised that studies show their city to be one of the world’s most content. Still, no one credited their happiness to the availability of services or economic prosperity, which is higher in this state than the rest of Mexico. One woman explained it more simply: “People know each other here.”

In Thrive, Buettner describes an afternoon he spends with three women he finds sitting on cinderblocks, chatting after the midday meal. He learns they meet here every day; also that their husbands support them and their multigenerational households on incomes of only about $500 a month.

Asked if they are happy, a woman named Silvia Idalia replies: “Yes, we’re happy. We could all use a little more money, but we have what we need, and what we don’t have God takes care of.” When asked what they would do with more money, the three women agree they’d buy bigger houses, but then reconsider: Bigger houses might prevent them from meeting here every afternoon.

Buettner says this conversation sums up Nuevo León’s “secret sauce” for happiness — factors beyond its solid civic structure that help residents thrive. Each of these women places a premium on community. Each has just enough money to care for the family, but doesn’t feel pressured to “run a status race” with friends and neighbors. They enjoy their time together, such that a bigger house seems less appealing than their daily ritual. Finally, each one expressed as key to her happiness a belief in a higher power that “takes care” of unmet needs.

Lesson from Nuevo León: Have Some Faith

Of all the lessons about happiness to be learned from Nuevo León, the importance of devoting time to family, friends and faith is key. Although Mexicans have a similar high rate of belief in a higher power as people in the United States, studies show they rate their beliefs as more important to their lives.

Attending a weekly religious ritual or meditation group is a simple way to get the benefits of both faith and community.

Faith can enhance our sense of purpose and meaning in daily activities, notes Buettner. Along with the benefits of greater social support, regularly attending some type of spiritual service offers a “means for ritualized stress relief and self-assessment.” Attending a weekly religious ritual or meditation group is a simple way to get the benefits of both faith and community.

One of Buettner’s colleagues, Ed Diener, PhD, in his book Happiness (Wiley-Blackwell, 2008), speculates that it’s the broader teachings of most faiths that most likely lead to greater happiness. These include “acting selflessly and morally, having a sense of purpose, finding meaning in daily activities, and expanding positive emotions on a continual basis.”

Regularly attending church, synagogue, temple or a weekly meditation group can all help build the more meaning-filled life that Diener describes, but spending regular, reflective time in nature or volunteering for a heartfelt cause provides many of the same benefits. All these activities offset feelings of isolation and emptiness, and foster a sense of connection and service that’s a hallmark of the “happiness zones.”

4. San Luis Obispo, California

While the United States ranks 20th in the World Database of Happiness, Buettner did discover one happiness zone tucked away in California. San Luis Obispo (SLO) is an exceptional American town. Drive-thru restaurants are illegal. Bike lanes line most streets. The town center is a traffic-free mission plaza.

This city of 44,000 displays “stratospheric levels of emotional well-being,” as well as superior physical health, according to a 2008 Gallup-Healthways study — obesity rates are almost 10 percent below the national average. Both facts are owed, in part, to thoughtful urban planning. People just don’t spend much time in cars.

“In SLO, there really [isn’t] a commute longer than 10 minutes,” Buettner notes. “Commuting is one of the things that Americans most dependably hate to do. Studies show that if a person with a $50,000 salary adds an hour to each end of her commute, she would need $20,000 more to compensate for the dissatisfaction.”

One of the satisfied citizens Buettner meets is Leslie Mead, who took a $25,000 pay cut to move to SLO from Santa Cruz. She left in large part to escape a long, traffic-choked commute to her former winemaking job, and she’s never looked back. “I understand unhappy people,” she told Buettner, “but I don’t understand unhappy people who are afraid of change.”

Still a winemaker, Mead now works at a small vineyard just seven miles from her house. The short drive takes her through pastures and vineyards, and she’s always glad to arrive at a job she loves. “I can’t think of another industry where people spend more of their personal time getting together to work,” she tells Buettner, referring to the number of tastings and other educational activities that wine-industry workers partake of regularly. She also spends time volunteering at the vineyard, where she started an English language program for farm workers, and where she participates in a company program to help these same workers gain easier access to housing and healthcare.

Lesson from San Luis Obispo: Live Close to Your Work

A key component of thriving, especially for Americans, is satisfying work. And a key component of satisfying work, Buettner emphasizes, is a short commute. “We know dependably that one of the things Americans hate is commuting by car,” he says.

Even better than a short drive is walking or biking to work. This is easy in places like San Luis Obispo, °Arhus or Monterrey, all of which have abundant sidewalks and bike lanes. By making exercise “the easy option,” these civic features facilitate active commutes that are a healthy part of people’s days. Activity levels in walkable communities are 35 percent higher than in communities where it’s difficult to get around, Buettner reports.

An additional advantage to reasonable commutes: They leave you surplus time and energy to live out your values. As one SLO resident told Buettner, “When you get home from a half-hour commute from work, there’s no way you’re going to feel like going to a city council meeting.”

By contrast, when your drive is short, or you walk or bike home — enjoying the breeze and waving to neighbors — you’re more likely to feel ready for anything.

Learn more about Buettner’s happiness project in his 2011 book, Thrive (National Geographic, 2010).