Spread the joy: Happiness is contagious

Happiness is contagious, even among strangers.

In a new study published in the British Medical Journal, US researchers tracked more than 4,700 people in Framingham, Mass., as part of a 20-year heart study. Participants were asked to measure their happiness based on the following questions:

- How often in the past week, did you enjoy life?

- Were you happy?

- Are you hopeful about the future?

- Do you perceive yourself to be as good as other people?

After analyzing the data, researchers found that happiness often happens in clusters, beyond what would be expected by chance. Happy people tend to have many friends who are also happy. And those with the most social connections living nearby -- friends, spouses, neighbors, and relatives -- were the happiest.

But researchers say this isn't simply a matter of happy people connecting with other happy people, which they do. In fact, the relationship between people's happiness extends up to three degrees of separation (for example, to the friends of one's friends' friends).

"Above and beyond, there is this contagious process going on," Nicholas Christakis, a professor in Harvard University's sociology department and co-author of the study, told Reuters.

Passing happiness on to strangers

So how does the happiness connection work among people who don't know each other?

"Imagine that I am connected to you and you are connected to others and others are connected to still others," Christakis said. "It is this fabric of humanity, like an American patch quilt."

Using this analogy, he suggested that each person is sitting on a different-colored patch. "Imagine that these patches are happy and unhappy patches. Your happiness depends on what is going on in the patch around you," he said.

The study also found:

- If you have a social contact who is happy, you are 15 per cent more likely to be happy.

- If a friend of a friend or the friend of a spouse or sibling is happy, your chance of happiness increases by 10 per cent.

- Take one more step: if a friend of that friend is happy, you could enjoy a 5.6 per cent chance of a happiness boost.

"Happiness is like a stampede," said Christakis. "Whether you're happy depends not just on your own actions and behaviors and thoughts, but on those of people you don't even know."

A few other interesting tidbits:

- Having a happy spouse helps, but not as much as having happy friends of the same gender.

- The ripple effect of happiness does not hold true among co-workers. Christakis says this may be due to the inherent competition in the workplace or even schadenfreude (happiness at someone else's expense).

- Unhappiness is not quite so contagious as happiness. Having a grumpy friend decreases your chances for happiness by about 7 per cent.

A happier, healthier society

Because happiness has been found to have an effect on a person's health, including reduced mortality, pain and illness, as well as improved cardiac function, the researchers believe that understanding how happiness spreads can help us learn to have a healthier society.

The bottom line: While you can pick up a flu bug from a friend, a neighbour or even someone you haven't met, you can also catch a smile and quite possibly, a lighter heart.