4. Join the club: According to research by Robert D. Putnam, author of Bowling Alone: The Collapse and Revival of American Community, joining a group that meets even once a month can produce the same happiness gain as more than doubling your income. Consider Monterrey, Mexico, where the average family makes only about $16,000 a year, yet residents rank high on the happiness scale, in part because they spend several hours a week interacting with neighbors, extended family, and faith-based groups. Humans evolved to be social creatures: Cooperation enabled us to outcompete other species for resources, and as a result, we tend to be happier when we're interacting with other people. Becoming part of a group at work—whether it's a small contingent of working moms in your company, or a larger industry-wide organization—will not only enhance your interests and talents but also give you the opportunity to build happiness-boosting social connections with your peers.

5. Become a mentor: There's strong data showing that volunteering your time can bump up your happiness. One good way to start is to become a mentor at work. Helping someone else achieve their goals emphasizes your strengths and takes your focus off your own problems.

6. Think twice before applying for a promotion: It sounds counterintuitive, but when it comes to long-term happiness, increases in personal income fail to provide much of a boost once household income rises above the $50,000-a-year threshold, according to research from Princeton University. Higher-paying jobs tend to be more demanding, with longer hours and more stress—leaving you less time and energy to put toward the things that do buy happiness.

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