A Gates scholar at the University of Cambridge, who pursues a doctorate in engineering, has released a happiness map of countries based on a study of tweets made by citizens on the popular social media platform Twitter.

Germany topped the table of happiest tweets, closely followed by Mexico, the US, the Netherlands and Denmark. Sweden was found to be the unhappiest.  The United Kingdom was ranked in 18th place among the 25 countries rated.

The map tracked those countries where there was enough tweeting to make the rating possible. The parameter used to determin the levels of happiness was the high-level correlations between words and emoticons. Alex Davies, who compiled the map, says that it was important to have a model that was not just linked to the use of English words, but also took into account the use of emoticons and expressions.

As tweets are very short, emoticons in them provide a good indicator of whether a person is happy or sad. But for tweets without emoticons, we have learnt to predict sentiment from the complex interactions between emoticons and words, says Davies in the release from the University.

Because of the high volumes of tweeting from the region, Davies was even able to break down the happiness rating by regions in countries such as the United States and Brazil. Tennessee and Colorado emerged the happiest states in the U.S. with Nevada and Mississippi being the least happy. New Yorkers and Californians were both ranked somewhere near the middle though New Yorkers were found to be slightly more upbeat than their West coast counterparts.