Is happiness contagious in online social networks?

The giggles -- they're contagious!
The giggles -- they're contagious!
Florence Delva/Getty Images

Have you ever noticed how infectious the giggles are? Even if you enter the conversation late and have no idea what the guffawing is about, you probably at least break into a smile. You just can't help it. The clatter of all that hilarity tickles the funny bone.

It turns out this is not just your imagination. A study conducted by researchers Nicholas A. Christakis and James H. Fowler, which charted the emotions of 4,739 people from 1983 to 2003, found that the happiness of other people does in fact have a strong effect on our own feelings of happiness.


Just how communicable is glee? It's powerful enough to spread through people who don't even know each other. Between two people who know each other, a happy person increases the other's happiness by 15 percent. A friend of a friend will increase happiness by 10 percent, and a third-degree connection can increase happiness by 6 percent. Mutual friends, or friends that name each other as close friends, seem to have the greatest affect on each others' bliss.

The study researched the contagion of happiness within traditional social networks. The question is: Is happiness just as catching in online social networks as it is in real-life social connections? In a separate but related study, Christakis observed 1,700 Facebook profiles. He determined that a person who posts a picture of him or herself smiling on Facebook is more likely to have online friends who are also smiling in their profile pictures.

But before we get to grinning profile pictures, let's take a look at what happiness is in the first place. What exactly does it mean to be happy?


What is happiness?

New brain research has shown that happiness can be measured. There are changes in the brain that can be observed when someone is happy. When someone is happy, one part of the brain is stimulated. Sadness, anger and other emotions are controlled by other portions of the brain. That's why it's possible for someone to feel both sad and pleasantly nostalgic when their child graduates or an elderly loved one passes away. Emotions are very complex and controlled by competing areas of the brain.

Happiness is an emotion that carries with it tremendous rewards. People who are happy tend to be healthier and more creative. In both the workplace and at home, they're more productive than people who aren't as content.


Happiness is determined by a wide range of factors. Genetic makeup plays a role in how happy we are. Our health is important in determining our general happiness, and, no matter how much we would like to deny it, our financial situation is a component of our happiness.

What has been underestimated in the past, however, is the importance of our social networks. A person who is at the center of a well-formed social network is more likely to be happy than someone without many social ties or who is on the outskirts of the social web. Happiness, as well as depression, anger and other emotions, seems to cluster in groups, so your choice of friends has a role in your happiness.

How much does your social network play into your happiness? It's suggested that having an extra $5,000 will not have as great of an impact on your happiness as the happiness of a friend of a friend's friend, who you don't even know. Pretty crazy, huh? But is the same thing true in the online world?


Happiness in Online Social Networks

So does happiness spread the same way through online social networks? Maybe. One study showed that someone who's smiling in their profile picture is more likely to have friends who smile in their profile pictures as well. Another study showed that people who were smiling in their picture had an average of one more friend than Facebook users who weren't smiling.

This research seems to follow the Christakis-Fowler study findings about how happiness clusters. People tend to cluster in happy groups. The people toward the center of that group are more likely to be happy than the people on the periphery. The same was verified in the Facebook study. People at the center of a social circle had more friends, and more smiling friends, in their networks than people on the edges of social webs. On the outskirts of the circle, even if the person is smiling in their profile picture, he or she is more likely to have friends who aren't and will have less friends overall.


To understand how it's possible for happiness to spread through a social network, it's important to understand how happiness spreads anywhere. There are three basic ways that happiness moves through a group of people:

Confounding is the term used to describe what happens when a group of people who are loosely connected share similar life experiences. An example of this would be a group of people who work in the same office or live in the same neighborhood. Positive experiences affect them individually and as a whole, as do negative experiences. This is one way people living in the same area may experience a cluster of happiness.

Homophily is when happy people choose each other as friends. Drawn together like magnets, happy people find others that share their life view and become friends.

Induction is the sensation of happiness in one person leading to happiness in others, through emotional contagion. Happiness is spread through who we choose as friends, shared life experiences, and hanging out with people who are emotionally wired for happiness. Can this translate to an online community? There is no firm answer, but there doesn't seem to be a reason why it wouldn't.


How Happiness Affects Others

If your Facebook friends are smiley, you're smiley. 
If your Facebook friends are smiley, you're smiley. 
Dimitri Vervitsiotis/Getty Images

While most people realize that it's important to take control of your own happiness, these new studies have shown an unexpected reason for this. In the past, it was thought that your emotions only affected you. We now understand that your happiness can affect not only you and your family, but people you don't even know. If online social networks mimic real life, then your happiness, or lack of it, could have a profound effect on people across the globe.

That doesn't mean you should ditch sad or negative friends. In fact, studies have shown that sadness doesn't hold nearly the emotional contagion power as happiness. Sadness in a social network doesn't spread as quickly or with as much strength as happiness. Researchers believe that this may be because we're wired as humans to take on what is best for us, so we're more susceptible to the power of happiness.


What about infecting the workplace with happiness? Is that possible? Unfortunately not. Unless you're genuinely friends with your co-workers, happiness won't spread, no matter how cheerful you are. Why? Researchers can only guess, but they believe that we are so hard-wired for competition in the workplace that a co-worker's happiness is interpreted as a threat. His or her happiness, you see, may come at our expenses.

The research on happiness and is its infectious nature is limited. The consensus among researchers is that the Christakis-Fowler study is intriguing, but it brings up as many questions as it answers. In the past, social contagion was linked to height, headaches and skin conditions. Further study, however, showed that the true link was environmental. Will further study on happiness prove the same thing?

And what about this idea that happiness spreads through online social networks? Do smiling Facebook pictures mean that people have caught happiness from one another, or is it a case of homophily, where happy people are attracted to each other? Or, perhaps it's neither, and rather the Facebook users posted smiling profile pictures so they wouldn't look grouchy alongside their friends -- a kind of online peer pressure.

For more information on social networks, visit the links on the next page.


Lots More Information

Related HowStuffWorks Articles

  • Belluck, Pam. "Strangers May Cheer You Up." The New York Times. Dec. 5, 2008. (May 12, 2009).
  • Christakis, Nicholas A. and Fowler, James H. "Dynamic Spread of Happiness in a Large Social Network: Longitudinal Analysis over 20 Years in the Framingham Heart Study." Dec. 4, 2008. (May 12, 2009)
  • Goleman, Daniel. "The Brain Manages Happiness and Sadness in Different Centers." The New York Times. March 28, 1995. (May 12, 2009).
  • Park, Alice. "The Happiness Effect." Time. Dec. 11, 2008. May 12, 2009.,9171,1865960,00.html.
  • Rampell, Catherine. "Other Potential Causes of Happiness." The New York Times. March 13, 2009. (May 12, 2009).
  • Stein, Rob. "Happiness Can Spread Among People Like a Contagion, Study Indicates." The Washington Post. Dec. 5, 2008. (May 12, 2008).