Existing evidence is dominated by western regions but researchers want to find out whether benefits are the same around the world

The science of happiness has spawned hundreds of thousands of studies, surveys, books and reviews, but what reliably lifts the spirits, to what extent, and who benefits most are still far from nailed down.

Now, psychologists have drawn up plans for the world’s largest happiness experiment to thrash out once and for all what really gives people an emotional boost, how effective different strategies are, and whether the benefits are the same around the globe.