Happiness really is contagious

Are you feeling a little down in the mouth this holiday season, what with the economic recession darkening your doorstep? Come on, get happy. You'll be glad to know happiness is about friends, not money. This is according to a new study by Harvard Medical School that studied the collective power of good vibes.

Researchers looked at 5,000 people over 20 years and found that when one person became happy, the network effect went up to three degrees away. That means if you get happy, it can trigger a social chain reaction over in one year or less that benefits not just your friends, but your friends' friends and your friends' friends' friends. This is the first study to show the indirect spread of happiness: You don't have to know the person in your extended social network to be in a better mood because he or she is happy.

One of the study's authors, James Fowler, says this indirect happiness works better than money in your pocket. Having an extra $5,000 in your wallet boosts your chances of becoming happier by roughly 2 percent, Fowler says. A friend of your friend who gets happy increases your chances of increased bliss by 10 percent. A friend of your friend's friend who gets happy boosts your chance to get happy by 5.6 percent.

And don't worry: This infection rate apparently doesn't work as well for sadness. So, smile as often as you can and think positive-recession or not. You really help make everyone's life a little better.