Switzerland, Iceland, Denmark, Norway and Canada lead in that order the list of 158 countries in being the happiest nations, according to the World Happiness Report produced by the Sustainable Development Solutions Network (SDSN).
Finland, the Netherlands, Sweden, New Zealand and Australia follow while Africa, Afghanistan and Syria lead from below.
The World Happiness Report 2015 shows that at both the individual and national levels, well-being is strongly influenced by the quality of existing social norms and institutions.
Jeffrey Sachs, Director of the Earth Institute, Columbia University and one of the editors of the report, says: "This report gives evidence on how to achieve societal well-being. It's not by money alone, but also by fairness, honesty, trust, and good health. The evidence here will be useful to all countries as they pursue the new Sustainable Development Goals."
Measures of well-being at the individual and national levels include family and friendships at the individual level, the presence of trust and empathy at the neighbourhood and community levels, and power and quality of the over-arching social norms that determine the quality of life.
"Countries with strong social and institutional capital not only support greater well-being, but are also more resilient to social and economic crises," Professor John F Helliwell, of the University of British Columbia, notes.
Six key variables in the report explain three-quarters of the variation in annual national average scores: real GDP per capita, healthy life expectancy, having someone to count on, perceived freedom to make life choices, freedom from corruption and generosity.
This year the report, which used the Gallup data, breaks down the data by gender, age, and region to reveal striking differences.
The report shows that a key national challenge is to ensure that policies are designed and delivered in ways that enrich the social fabric, and teach the power of empathy to current and future generations.
First released in 2012, the report drew international attention as a landmark survey of the state of global happiness. The report contains analysis from leading experts in the fields of economics, neuroscience, national statistics, and describes how measurements of subjective well-being can be used effectively to assess national progress.
A Gallup poll released last month on International Day of Happiness on Friday (20 March) had found Paraguay and Latin America to be the happiest places to live in the world.
Meant to measure the things GDP was not intended to measure, researchers asked 1,000 people from each country whether they were well-rested, treated with respect, smiled or laughed a lot, learned something interesting, and whether they experienced positive feelings during the day before the survey.
The US came in 15th, while the United Kingdom was tied at 43rd and India came in at 39th.
Afghanistan, Bosnia and Herzegovina, Georgia, Lithuania and Nepal were ranked the saddest countries of all.