Gallup's 2011 global ranking of thriving and suffering found those thriving tended to have higher incomes, more education, good health and social support. Those suffering often have lower incomes, less education and less access to basic needs such as food, shelter and healthcare.
About 1,000 people ages 15 and older in each of the 146 countries were asked to rate their current and future lives on a ladder scale, with steps numbered from zero to 10 based on the Cantril Self-Anchoring Striving Scale.
Gallup considers people to be thriving if they rate their current lives a 7 or higher and project their lives in five years at 8 or higher, and classifies people as suffering if they rate their current lives at 4 or lower and their lives in five years a 4 or lower.
Suffering spiked in places such as Iran, Afghanistan and El Salvador in 2011. Suffering increased the most in El Salvador, climbing to 33 percent in 2011 from 9 percent in 2010, the surveys said.
The research found suffering declined the most in Macedonia, falling 25 percentage points last year from 38 percent in 2010.
Suffering was as low as 1 percent or less in the United Arab Emirates, the Netherlands, Luxembourg, Canada, Thailand and Brazil.
Notable deaths of 2014 [PHOTOS]