Happiness is contagious, according to a new study:

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.

The lesson is that taking control of your own happiness can positively affect others, says James Fowler, co-author of the study and professor of political science at the University of California in San Diego . . .

If you are the hub of a large network of people — that is, if you have a lot of connected friends or a wide social circle — you are more likely to become happy, the study found.

The bad news is that obsesity and smoking are also contagious.