Why I Love Posting Happy Things, and Frequently Interrupt Bad News Days with Random Silliness

Because all of us sort of intuitively know this:

Happiness is contagious, spreading among friends, neighbors, siblings and spouses like the flu, according to a large study that for the first time shows how emotion can ripple through clusters of people who may not even know each other.

The study of more than 4,700 people who were followed over 20 years found that people who are happy or become happy boost the chances that someone they know will be happy. The power of happiness, moreover, can span another degree of separation, elevating the mood of that person's husband, wife, brother, sister, friend or next-door neighbor.

...Previous studies have documented the common experience that one person's emotions can influence another's -- laughter can trigger guffaws in others; seeing someone smile can momentarily lift one's spirits. But the new study is the first to find that happiness can spread across groups for an extended period.

When one person in the network became happy, the chances that a friend, sibling, spouse or next-door neighbor would become happy increased between 8 percent and 34 percent, the researchers found. The effect continued through three degrees of separation, although it dropped progressively from about 15 percent to 10 percent to about 6 percent before disappearing.

This study says the effect only works in close physical proximity, but I suspect that's inaccurate, though it may well be observable only in close physical proximity. Then again, internet communities may not have been part of the study, since they didn't exist 20 years ago.