Happiness is in the air at least that is the conclusion of a new study published in the British Medical Journal. More exactly, researchers from Harvard Medical School suggest that people that are happy around you make you happy too. This makes happiness a contagious “disease,” we would love to share with everybody around us.

“We’ve known for some time that social relationships are the best predictor of human happiness, and this paper shows that the effect is much more powerful than anyone realized,” Daniel Gilbert, professor of psychology at Harvard University, said.

The study analyzed information on the happiness of about 5,000 people and their friends, neighbors, relatives and co-workers over 20 years. It found that a person’s proximity to happy people could make them happy too. To be more specific, the prospect of happiness can be significantly boosted by living with a happy partner or near a happy friend.

“Changes in individual happiness can ripple through social networks and generate large scale structure in the network, giving rise to clutters of happy and unhappy individuals. Most important from our perspective is the recognition that people are embedded in social networks and that the health and wellbeing of one person affects the health and wellbeing of others,” Prof. Nicholas Christakis from Harvard Medical School and Prof. James Fowler from the University of California, lead authors of the study, said.

For example, a happy friend who lives within a mile, boosts your odds of being happy by 25 percent, researchers found. A happy sibling within the same distance increases your probability of happiness by 14 percent. Even the happiness of a friend’s friend boosts your chance of being happy by nearly 9.8 percent. What’s more than this? The happiness of a friend of a friend of a friend increases your chance of being happy by 5.6 percent.

The good news is that only happiness is contagious. On the other hand, unhappiness did not spread as much.

The study further discovered that the closest a happy person is to us in terms of distance the highest our chances of being happy are. It found that a next-door neighbor’s joy made the odds of a person being happy go up by 34 percent, while a down the block neighbor’s good spirits had no such effect.

Moreover, a friend living one mile away could increase one’s happiness by 41 percent, but the effect decreased as the space between friends is wider. For example, for a friend from a different community, no impact on the level of happiness was registered.