An analysis of 3,800 randomly chosen Twitter users found that emotions spread virally through Twitter feeds — with positive emotions far more likely to spread than negative ones. Just before I read this study I was reading and lurking through some twitter-discussions and to be honest, they weren’t that friendly. But still maybe Twitter was right  in changing the star for a heart?

From the press release:

“What you tweet and share on social media outlets matters. Often, you’re not just expressing yourself — you’re influencing others,” said Emilio Ferrara, lead author of the study and a computer scientist at the USC Viterbi School of Engineering’s Information Sciences Institute. Ferrara collaborated with Zeyao Yang of Indiana University. Their study was published by the journal PLOS One on Nov. 6.

Ferrara and Yang used an algorithm that measures the emotional value of tweets, rating them as positive, negative or neutral. They compared the sentiment of a user’s tweet to the ratio of the sentiments of all of the tweets that appeared in that user’s feed during the hour before. Higher-than-average numbers of positive tweets in the feed were associated with the production of positive tweets, and higher-than-average numbers of negative tweets were associated with the production of negative tweets.

About 20 percent of Twitter users were deemed highly susceptible to what the researchers described as “emotional contagion” — with more than half of their tweets affected. Those users were four times more likely to be affected by positive tweets than negative ones.

Those least likely to be affected by emotional contagion were still a little less than twice as likely to be affected by positive tweets as negative ones. Over all users, regardless of susceptibility, positive emotions were found to be more contagious than negative emotions. This may be relevant to plan interventions on users experiencing depression or other forms of mood disorders, Ferrara said.

The study builds on decades of research demonstrating first that emotions can be spread through person-to-person contacts, and now finding that they can spread through online interactions as well.

Facebook drew criticism last year for attempting to demonstrate a similar effect by tweaking 700,000 users’ news feeds. Unlike that experiment, Ferrara and Yang did not manipulate what Twitter users were experiencing — rather, they simply observed what was already happening and analyzed it.

Abstract of the study:

Social media are used as main discussion channels by millions of individuals every day. The content individuals produce in daily social-media-based micro-communications, and the emotions therein expressed, may impact the emotional states of others. A recent experiment performed on Facebook hypothesized that emotions spread online, even in absence of non-verbal cues typical of in-person interactions, and that individuals are more likely to adopt positive or negative emotions if these are over-expressed in their social network. Experiments of this type, however, raise ethical concerns, as they require massive-scale content manipulation with unknown consequences for the individuals therein involved. Here, we study the dynamics of emotional contagion using a random sample of Twitter users, whose activity (and the stimuli they were exposed to) was observed during a week of September 2014. Rather than manipulating content, we devise a null model that discounts some confounding factors (including the effect of emotional contagion). We measure the emotional valence of content the users are exposed to before posting their own tweets. We determine that on average a negative post follows an over-exposure to 4.34% more negative content than baseline, while positive posts occur after an average over-exposure to 4.50% more positive contents. We highlight the presence of a linear relationship between the average emotional valence of the stimuli users are exposed to, and that of the responses they produce. We also identify two different classes of individuals: highly and scarcely susceptible to emotional contagion. Highly susceptible users are significantly less inclined to adopt negative emotions than the scarcely susceptible ones, but equally likely to adopt positive emotions. In general, the likelihood of adopting positive emotions is much greater than that of negative emotions.