Happiness is infectious

Good news - you can "catch" happiness from those around you. The BBC carried the story. And now we have numbers to pin down this phenomenon.

Live-in partners who become happy increased the likelihood of their partner being happy by 8% and similar effects were found for siblings living close by (14%) and neighbours (34%).

Close physical proximity seems to be important for the spread of happiness - a person was 42% more likely to be happy if a friend who lives less than half a mile away becomes happy; this effect declines with greater distance.

The cynics and pessimists among us will wonder if happy people are simply less likely to associate with unhappy ones. But the study found that the relationship between people's happiness levels seemed to extend up to three degrees of separation - to the friend of a friend of a friend.

Happiness is good for your health. Cultivate your social network - phone a friend. Smile!
But is happiness really as simple as putting on a happy face? "In a very limited way, yes," says professor of psychology and "face reader" Paul Ekman. "The trick with happiness is that while everybody can smile, most people can't move one crucial muscle around the eyes that must be moved to generate the physiology of happiness. ... In a fake smile, only the zygomatic major muscle, which runs from the cheekbone to the corner of the lips, moves. In a real smile, the eyebrows and the skin between the upper eyelid and the eyebrow come down very slightly."