Happiness is contagious in social networks

If you're feeling great today, you may end up inadvertently spreading the joy to someone you don't even know.

New research shows that in a social network, happiness spreads among people up to three degrees removed from one another. That means when you feel happy, a friend of a friend of a friend has a slightly higher likelihood of feeling happy too.

This network from 2000, coloured for average mood,
shows yellow as happy, blue as sad, and green as
in-between.

More here from CNN.............