WHAT IS THE perfect way to track a person’s mood? Read their Twitter account.

A new study, published in Science journal, says that it is possible to track mood rhythms across the globe using the social networking site, where people ‘tweet’ their thoughts using just 14o characters.

The study, by Scott A Golder and Michael W Macy, found:

… that individuals awaken in a good mood that deteriorates as the day progresses—which is consistent with the effects of sleep and circadian rhythm—and that seasonal change in baseline positive affect varies with change in daylength.

They also discovered that – perhaps unsurprisingly – people are happier on weekends, all thanks to sleep-ins: “the morning peak in positive affect is delayed by 2 hours, which suggests that people awaken later on weekends”.

In January 2010, the duo sampled all Twitter user accounts created between February 2008 and April 2009, collecting up to 400 messages from each account – 509 million in total.

The researchers studied and rated words according to how positive or negative they were in order to assess what the twitterer’s mood was.

Because of the variations in gender, race and age of Twitter users, they believe their sample includes far more diverse demographic categories than earlier studies.

Nicholas Christakis, a professor of medical sociology at Harvard Medical School, told USA Today that Twitter was “a whole new way for social scientists to understand human beings”.