Twitter Happiness map

Cambridge University PhD student Alex Davies developped Twitter Happiness map. The map is based on the ratios of happy and sad tweets made by people from different countries.

According to the map Germany is the happiest country in the world. It is followed by Mexico, the US, the Netherlands and Denmark. Among the US states Tennessee is the happiest.
I doubt it’s possible to calculate happiness levels from the words used in tweets, but the map itself is quite curious.