From social media to advertising, happiness is everywhere you look. And it isn't healthy, suggests new research.
The United States is richer than ever, but GDP isn't everything.
Responses from 200,000 British people revealed that mental health and relationships affect happiness the most.
Scientists believe there is no basis for the claim that optimism is fundamental to human psychology.
Big data from around the world points to a single, clear answer to the perennial question.
In Bhutan they measure the happiness of the population alongside the usual economic data.
Measuring happiness can have sad drawbacks, some argue.