This may come as a surprise to the "Me Generation," but happiness doesn't come from living in a big house, buying the latest techno-gadget, and getting stamps from exotic locales in your passport.

　　In fact, a 2005 poll by Time Magazine found that helping others was a major source of happiness for 75 percent of Americans."Volunteering is an opportunity to be socially engaged and contribute to the lives of others," says Stephen Post, a professor at Case Western Reserve University who co-authored the book Why Good Things Happen to Good People with Jill Neimark. "It's not material goods that make us happy—it's having purpose and meaning in our lives."

　　In fact, some recent research suggests that we're actually hard-wired for helping. Even thinking about helping others is enough to stimulate the part of our brain associated with feel-good chemicals like oxytocin.Helping others doesn't just make us happier, there's also evidence it makes us healthier too. "Recent research out of England shows that cities with higher rates of volunteerism had the lower rates of depression and heart disease," says Post.

　　Don't have a lot of free time? No worries. People who volunteer just two hours per week (100 hours per year) enjoy lower rates of depression and better physical health.