Mar 25, 2009: Happiness Is Contagious

Scientists around the world have confirmed—happiness is contagious. A review published in 2008 in the British Medical Journal summarizes the findings of an ongoing study of the residents of Framingham, Massachusetts, which since 1948 has measured risk factors for cardiovascular disease. Nicholas Christakis, a medical sociologist at Harvard Medical School, reports that the study incidentally proves some familiar and reveals some startling new facts about happiness.

Happy people cluster together and are healthier overall. The more connected you are emotionally to a happy person, the more your own happiness increases. Surprisingly, not only your friends’ moods, but your friends’ friends’ friends’ moods affect your happiness. In fact, happiness spreads through three degrees of separation.

If a good friend who lives a few miles away suddenly becomes happy, you are 60% more likely to become happy yourself. If the newly happy person is a next door neighbor you know casually, your benefit drops to 30%. Surprisingly, the sudden happiness of a spouse only has a 10% chance of increasing your own happiness. This may be partly because we are most affected by the happiness of friends of the same gender.

How does happiness spread? We instinctively copy the facial and body language of people we are around. Elaine Hatfield at the University of Hawaii, Honolulu, suggests that the observer feels a “pale reflection of their companions’ actual emotions.” Scientists at the University of Tübingen, Germany, found that the stronger the facial expression, the stronger the emotion of the person observing. In other words, if you are with someone who looks afraid, your own fear response will be triggered. Conversely, being around someone who smiles a lot will trigger your own happiness.

In fact, Duncan Watts of Columbia University has demonstrated that injecting a person with a particular behavior into a group can spread that behavior like an infection through the whole group. We’ve all seen one negative person wreck a meeting. Happiness spreads the same way.

How can you maximize your own happiness? If you are around someone whose mood or behavior negatively affects you, insulate yourself from infection by avoiding the natural tendency to mirror their expressions and body language.

Surround yourself with positive, upbeat friends. Spend as much time as you can with people whose moods and behavior you admire. Joining a group with interests similar to your own is good. Even better is to socialize with the members as often as possible.

Remember that happy people attract other happy people. Cultivate contentment and gratitude in your own life, and watch the happiness spread.