Contagious emotion

When you express yourself on Facebook, do you ever think that it can change what your friends write? You might not be writing for anyone in particular. You might even feel like you’re just shouting into the wind. But the science of interaction shows the things you write have a small effect. Posts you write about your own emotions could end up being reflected in the emotions others write about. Research has found that your own Facebook status updates could affect your friends' posts, even days later.

The power of words?

Psychologists have studied how people transmit emotions to one another, almost like viruses. It’s useful to be able to share emotions; it helps us bond with someone else. But most research so far has been on people sharing emotions in person. Some psychologists even think that most emotions are shared through physical cues rather than words. But now that we communicate more in text, research is beginning to show it’s possible to affect someone else’s emotions even if you’re not with them. Adam Kramer, a researcher at Facebook, wanted to see whether emotional status updates led to friends posting about similar emotions.

No need to be nice

There is an interesting advantage to studying Facebook status updates. They are written for a large group rather than to any particular person, which means any shared feelings are more likely to be true. If someone sent you an emotional text, it would be rude not to respond, and sometimes you might pretend to share a certain emotion just to be nice.

No one in particular needs to reply to a status update, so if you don’t share the emotion you don’t have to say anything similar. If Facebook statuses seemed to mimic emotion, it’s a clue that it really is possible for your posts to influence the emotions that others post about.

Collecting feelings

Adam started by selecting about 60,000 people on Facebook – a group of users and all their friends – who had posted something three days in a row. Then he gathered all the status updates they wrote over those three days. He analysed all the words they used with the help of a special dictionary for emotion research, which rates words according to whether they have positive or negative meanings. His prediction was that he would see users and their friends using words associated with the same sort of emotion.

He did. Not only were users likely to post about similar emotions on the same day, the effect seemed to stick around for at least a couple of days afterward. Imagine you post about being happy. What Adam found was that if he compared your friends’ posts tomorrow to your posts today, they would tend to be happy posts too. Your friends’ posts would even show similar emotions to your original posts after two days. They even found that if one person posted about a certain emotion, it could stop others from posting an opposite emotion. For example, when people expressed positive emotions in their status updates, their friends held back from posting about negative emotions.

You’re influential

So it turns out that the words you use on Facebook influence your friends’ choice of words too. Adam points out that you may not be affecting your friends themselves. Others will have to do more research about whether your Facebook posts can directly give other people the same emotions as you. But just by posting on Facebook, you change what your friends post about. That’s not to say that you have to follow the crowd. In fact, it’s probably better that you say what you’re thinking, without worrying whether others are saying it too. Your friends can feel good for you when things are going well, and they can help if things are troubling you. But the next time you write a post, it’s interesting to think that you might be helping in a small way to bring thousands of other posts into existence too.