Happy?

It's simple, really: Treat other people as if they were the key to your happiness -- science tells us that they are.

Of course, how we treat people and how we interact with them -- from eating with your family to introducing yourself to the new neighbors -- is all a matter of choice, which leads us to "V," the final part of our equation.

VOLUNTARY NATURE OF HAPPINESS

"V" is really about the everyday things we do to create happiness. Anyone who has slogged through a dead-end job counting the hours until quittin' time already knows that the right job is a big part of day-to-day happiness. But finding good, meaningful work -- what Haidt refers to as a "calling" -- is easier said than done. (That's why they call it work, Grasshopper.)

"People often think 'I'll be happy when,' " says Pete Cohen, a life coach and co-author of "Feeling Good for No Good Reason" (How To Books, 1999). But then we get whatever it is we're chasing -- a raise, a promotion, a good solid kick of the pigskin -- and it turns out we never really find joie de vivre.

The key is to tap into what Hungarian-born psychologist Mihaly Csikszentmihalyi describes in his book "Flow: The Psychology of Optimal Experience" (Harper & Row, 1990) as the total immersion that happens when "people are so involved in an activity that nothing else seems to matter." Instead of focusing on the destination, we'd do better to enjoy the journey -- the work that leads to the raise rather than t he raise itself.

Not a 9-to-5 type? Don't fret. Debbie Gisonni, author of "The Goddess of Happiness (Inner Ocean Publishing, 2005), recommends thinking back to childhood and remembering the things that made you happy then. Maybe your pathway to "flow" is raising kids, painting murals, singing in the church choir -- anything that plays to your strengths and is rewarding for its own sake, rather than for the end goal. (See "Who Is Happiest?" at left for more on child-rearing and happiness -- or the lack thereof.)

"In order to enjoy life, you must do enjoyable things. Read nice books, enjoy sports," says Veenhoven. "Take time for enjoyment; there's nothing wrong with that." It sounds like no-brainer advice, but somehow we forget the happiness of the warm puppy in the scramble of housetraining, heartworm medication and veterinary appointments.

Part of the problem might be our priorities. The Declaration of Independence describes "the pursuit of happiness" as an inalienable right, but how many of us pursue it regularly? (And if we're not chasing happiness, then what are we chasing?) Maybe we could learn a thing or two from the nation of Bhutan, a tiny Buddhist kingdom nestled in the Himalayas. In 1972, the king of Bhutan decided to ditch the gross-domestic-product measurement in favor of policies that promote gross national happiness. Since then, the government has focused on what it calls the "four pillars" of GNH: socio-economic growth, cultural values, environmental conservation and good governance. In the Bhutanese model, good government makes its people happy, not necessarily rich.

Though the U.S. Census has yet to include a line item addressing household happiness, that doesn't mean you can't establish your own pillars of happiness. After all, the equation has been provided for you, and unlike high school math class, there's no wrong answer -- as long as you're happy.