Social scientists have long known that social networks tend to have an “assortative” character – people are more likely to have friends who are similar in age, nationality, race or education, and less likely to be linked to people who are different. Psychologist Johan Bollen of the University of Indiana and colleagues wondered if this property might extend to an online network like Twitter, and whether it was true for levels of happiness.
To find out, they tracked 102,000 Twitter users over six months, analysing the 140-character-or-less text from 129 million of their tweets with standard techniques from psychology. Specifically, they measured the emotional content of the tweets as reflected in the presence of positive or negative words from a lexicon previously established by psychologists. From this they could assess the “subjective well-being” of the users through their tweets.
The researchers indeed found that happier people – those recording a high subjective well being – tended to be tweeting and receiving tweets from people who were also happier. The same was true for those who were less happy.
“It turns out that Twitter users are preferentially linked to those with whom they share a similar level of general happiness,” says Bollen.
He admits they don’t yet know why this is true. Happy or unhappy people may simply seek one another out, drawn by tweets expressing emotions similar to their own. Or, Bollen suggests, it could be that the emotions expressed even in short tweets have an infectious quality, lifting peoples’ spirits or filling them with gloom, depending on what they read.
Journal reference: http://arxiv.org/abs/1103.0784