The happiest places in the world are those where enlightened leaders shifted their focus from economic development to promoting quality of life.

“The biggest predictors of happiness are tolerance, equality, and healthy life expectancy,” Dan Buettner, a National Geographic writer and the author of The Blue Zones of Happiness, said Saturday at the Spotlight Health Festival, which is cohosted by The Aspen Institute and The Atlantic.

Buettner’s work found that Denmark, Costa Rica, and Singapore were the happiest places on Earth, in terms of how their citizens rated their own well-being. The U.S. was the 18th happiest. As Buettner wrote in National Geographic: “[A]bout three-quarters of human happiness is driven by six factors: strong economic growth, healthy life expectancy, quality social relationships, generosity, trust, and freedom to live the life that’s right for you.”

But, as Buettner noted, while the happiest places share many things in common, they each have unique factors that promote happiness. In Costa Rica, for instance, he said happiness can be attributed to the pleasure of living daily life; people smile, laugh, and interact with their friends and neighbors.

Denmark, meanwhile, exemplifies a society in which the state takes care of basic needs, such as education and health, leaving citizens to pursue their passions. Other Scandinavian countries do well in the World Happiness Index for the same reasons.