Jetpac is a genius app that analyzes Instagram photos to create city guides. It identifies markers like how much lipstick people are wearing, or the number of mustaches showing, to rate places like, for example, "bars women love” or "hipster hangouts”.

The app recently turned its tech to happiness. By crunching through 150 million images and awarding "smile scores" based on the incidence and strength of smiling, it ranks the world's happiest places - and you'll be surprised by the results.

Latin America, is the happiest continent, with a score of 51.5. Brazil (60.5) is its happiest country; Argentina (30.0) its least happy. North America is next, with Nicaragua (59.4) first and the U.S. Virgin Islands (19.2) the grumpiest. Asia comes in least happy among continents, with Japan achieving a smile score of 9.8 (why the gloomy faces, Tokyo?).

Analyzing pictures on social media is, of course, not exactly scientific. The results could just show how happy people were when they were Instagramming their adventures. Also, let's not forget happy photos where people aren't smiling - like duckfaces, screams, smizes, and well, you get the picture.