According to a new survey, Denmark is the world's happiest country while Burundi is the least happy.
The fourth World Happiness Report also found that countries where there was less inequality were happier overall.
Switzerland, Iceland, Norway and Finland, which like Denmark have strong social security systems, made up the rest of the top five.
The US was the world's 13th happiest country, the UK was 23rd, China was 83rd and India was 118th.
At the bottom of the 156 countries on the list was Burundi, which is experiencing severe political unrest and the threat of violence.