(AFP) - The world is becoming a happier place, a study published in this month's Perspectives of Psychological Science shows.
Data from national surveys conducted between 1981 and 2006, which were collated by researchers at the University of Michigan Institute for Social Research, showed that happiness was on the rise in 40 out of 52 countries.
University of Michigan political scientist Ronald Inglehart, the lead author of the study, said the upswell in happiness came as a surprise to researchers.
"It's widely believed that it's almost impossible to raise an entire country's happiness level," he said.
"Important events like winning the lottery or learning you have cancer can lead to short-term changes, but in the long run most previous research suggests that people and nations are stuck on a 'hedonic treadmill,'" Inglehart said in a statement.
"The belief has been that no matter what happens or what we do, basic happiness levels are stable and don't really change."
But the University of Michigan study, which was part of the ongoing World Values Surveys, appeared to disprove that theory.
World Values Surveys have asked, for the past 26 years, more than 350,000 people how happy they are.
Among the 52 countries for which long-term comparative data were available, India, Ireland, Mexico, Puerto Rico and
South Korea showed steep upticks in happiness last year, while the happiness quotient in 14 other countries, including nine in Europe, also rose, but less sharply.
Those 14 countries are Argentina, Canada, China, Denmark, Finland, France, Italy, Japan, Luxembourg, the Netherlands, Poland,
South Africa, Spain and Sweden.
In the United States, Switzerland and Norway, happiness was stagnant, but all three countries were still in the top 20 of 97 nations, representing 90 percent of the world's population, that were ranked in order for happiness.
Denmark ranked at the top of that list and Zimbabwe at the bottom.
"Happiness and life satisfaction rise steeply as one moves from subsistence-level poverty to a modest level of economic security and then levels off," the study says.
"Among the richest societies, further increases in income are only weakly linked with higher levels of subjective well-being," it says.
How happy a country is, is also strongly related to how democratic it is, said Inglehart.
"The results clearly show that the happiest societies are those that allow people the freedom to choose how to live their lives," Inglehart said, citing the tolerant social norms and democratic political systems in Denmark, Iceland, Switzerland, the Netherlands and Canada -- all of which rank among the 10 happiest countries in the world.
