Indians may not be the happiest people in the world yet but happiness in India shows "steeply rising trends" as the world becomes happier by the day, a new survey suggests.

The happiest country in the world is Denmark with its democracy, social equality and peaceful atmosphere, according to the World Values Survey, funded by the U.S. National Science Foundation.

Zimbabwe, torn by political and social strife, is the least happy, while the world’s richest nation, the U.S., ranks 16th, according to the survey done regularly by a global network of social scientists.

It found increased happiness from 1981 to 2007 in 45 of 52 countries analyzed. "In several of these countries — India, Ireland, Mexico, Puerto Rico and South Korea — there are steeply rising trends" of happiness, it said.

"I strongly suspect that there is a strong correlation between peace and happiness," said Ronald Inglehart, of the University of Michigan’s Institute for Social Research, who directed the study.

"Denmark is the happiest country in the world in our ratings," he said, noting, "Denmark is prosperous — not the richest country in the world but it is prosperous."

Many other countries also show a clear trend toward increased happiness, including Argentina, Canada, China, Finland, France, Italy, Japan, South Africa and Sweden.

Happiness in the U.S., Switzerland and Norway remains unchanged. Only four countries — Austria, Belgium, Britain and West Germany — show downward trends.