It's a difficult thing to measure, happiness.
Is it perceived? Or is it experienced? Are the happiest people the ones who say they are? Or are they the ones who have the most positive experiences — the ones who feel most respected, are least stressed and smile or laugh most often?
The difference may seem subtle, but ask those questions and you'll get very different answers.
"It creates this debate as to which one is happiness," says Jon Clifton, managing director of global analytics for the research organization Gallup.
If perception rules, then the Danish and Swiss are the happiest in the world, according to a recent United Nations report based on Gallup data over several years. If experience is what matters, then the crown goes to Latin America, according to Gallup's separate analysis of last year's data.
Both are based on Gallup's annual surveys of roughly 1,000 adults from more than 140 countries, but each yields very different results.
Where people say life is good
Imagine a ladder with 10 rungs. The top represents your best possible life. The bottom represents your worst possible life. Where does your actual life fall on the ladder?
That simple scenario and question — developed by social researcher Hadley Cantril — lies at the heart of the U.N. analysis, the 2016 update to its World Happiness Report released this month.
It found that Europe dominated the top 10 list of happiest countries, based on an analysis of Cantril ladder ratings collected by Gallup in 2013, 2014 and 2015 and totaling about 3,000 replies in each of more than 150 countries.
Europe was home to seven of the 10 countries whose residents reported the highest average life evaluations. The remaining three were Canada, New Zealand and Australia. The United States ranked 13th.
The bottom of the list was dominated by Africa, which served as home to eight of the bottom 10 countries. The other two were Afghanistan and Syria.
Happiness, the U.N. report finds, is most unequal in two regions: the Middle East and North Africa, and Latin America and the Caribbean. The charts below show the spread of scores in each region of the world.
But what drives the differences among countries?
The U.N. team found that three-fourths of the variation could be explained by six indicators: economic output — or gross domestic product — per person; healthy years of life expectancy; having someone to count on in times of trouble; trust in government and business; perceived freedom; and generosity.
Three of those mattered most: incomes, social support and healthy life expectancy.
Money appears to be very closely tied with life evaluation — on that, Gallup's Clifton agrees. But, he says, there's another happiness measure that is far less tied to finances: life experiences.
"That's where you see that some of the poorest countries in the world — Paraguay, Guatemala, for example — are some of the ones that say that they laugh and smile the most or experience the most enjoyment," he says.
Where the lived experience is good
Existing indicators such as economic output or income per capita don't fully capture life experience, so Gallup created its own by asking people about their day.
Did you feel well-rested yesterday? Were you treated with respect all day? Did you smile or laugh a lot? Did you learn or do something interesting? Did you experience enjoyment?
The "yes" responses to those questions were averaged to create Gallup's Positive Experiences Index, a measure of happiness that ranges from 0 to 100. The good news is that positive experiences are on the rise globally: The index rose from 68 a decade ago to 71 last year.
More than 70 percent of respondents said they were rested, felt respected, smiled or laughed a lot or felt enjoyment the day before they were surveyed. More than half learned or did something new.
Latin American countries dominated the top 10 list. Four of the top 10 countries — Costa Rica, El Salvador, Guatemala and Honduras — were in Central America. Another four — Colombia, Ecuador, Paraguay and Uruguay — were in South America. The remaining two were Uzbekistan and Indonesia. The United States ranked 25th.
The Middle East and North Africa were home to some of the lowest scores on the index, with several of the countries there, including Iraq, Yemen, Turkey and Syria, suffering from internal strife.
The scores are strongly correlated to perceptions about living standards, personal freedoms and the presence of social networks, Gallup found. Culture plays a role, too.
"That so many people report positive emotions in Latin America at least partly reflects the cultural tendency in the region to focus on the positives in life," Gallup noted in the report. "In fact, the single variable that predicts results on both the Positive and Negative Experience Indexes is the country of origin, suggesting cultural bias exists in how people answer these questions."
Thailand is all smiles
In most countries, at least two-thirds of people said they smiled or laughed a lot the previous day. But the range in such reports was wide: The distribution ranged from as low as 39 percent in Turkey to as high as 91 percent in Thailand.
A respected world
In all but a dozen countries, 75 percent or more of the population surveyed reported feeling respected the day before. That rate was at or above 95 percent in each of the top 10 countries, all but three of which — Uzbekistan, Portugal and Kuwait — were in Latin America. The United States ranked 56th, with 79 percent reporting smiling or laughing a lot the prior day.
Where the lived experience is bad
Gallup didn't just focus on the good life. It also asked respondents about the opposite: Did they spend a lot of the day before in physical pain, worried, sad, stressed or angry? The responses to those five questions comprised the Negative Experience Index, which like its positive counterpart rose over the past decade. The index, which can range from 0 to 100, is up from 24 a decade ago to 28 today.
More than a third of people globally reported experiencing a lot of worry or stress the day before they were surveyed, making those the most-held negative experiences. Just 1 in 5 was angry much of the prior day — the least-common of the five negative experiences.
Africa and the Middle East were home to 7 of the top 10 countries with the highest shared negative experience.
Iraq led the list, as it did in 2011, 2013 and 2014. Adult Iraqis are sadder and report feeling more physical pain than their peers in any other country surveyed. The nation is second in worry, stress and anger, too. Iran scored second on the overall negative emotions index, followed by Syria.
"The continued presence of Iraq and Iran at the top of the list is not that surprising given how strongly related negative scores are to people’s perceptions about their living standards and health problems," Gallup reported. "In fact, people in most of the countries with the highest negative scores in 2015 were contending with some disruption — economic or otherwise."
The African countries of South Sudan, Liberia, Togo and Sierra Leone also made the top 10. The three countries in the top 10 outside of those regions were Cyprus and Portugal in Europe and Bolivia in South America.
For the vast majority of countries, negative experiences were relegated to a minority of the population. Only in Iraq and Iran was the Negative Experience Index above 50 — meaning, on average, more than half of those surveyed reported having each of the five negative experiences.
In only three countries — Iraq, Ivory Coast and South Sudan — did a majority of the population report experiencing a lot of physical pain the day prior. In just two countries — Iraq and Syria — majorities reported experiencing sadness. And a majority in just one country, Iran, reported feeling angry a lot the day before being surveyed.
In 29 countries, most of the population reported worrying a lot, while majorities in nine countries reported feeling stressed a lot, with the United States bringing up the rear of that list.
Bonus: The most emotional countries
Latin America was home to all but one of the world's most emotional countries, defined as those who reported the most positive and negative experiences. The list of least-emotional countries — those whose populations reported the least positive and negative experiences — was dominated largely by countries with ties to Russia and the former Soviet Union.