(Medical Xpress)—Much research has demonstrated a link between individuals' emotional and physical health. For example, depression and stress have been tied to self-reports of increased pain, fatigue and disease, whereas positive emotions have been tied to decreases in those ailments.

There is, however, a caveat. Nearly all of this research is limited to industrialized nations – places where individuals' basic needs like food and shelter are typically met. This has left unanswered the question of whether the emotions-health link also exists in undeveloped nations.

Absent research from these poorer countries, many observers have speculated that the emotions-health link isn't universal across the world, theorizing that emotions are a "luxury" that only first-world inhabitants can afford to focus on because their more basic needs are being met.

But a new study by University of Kansas researcher Shane Lopez finds this speculation is wrong. According to Lopez, the emotions-health link exists across nations and, perhaps most surprisingly, is even more pronounced in lesser .

"It seems plausible that the emotions-health link wouldn't exist in poor nations where people have more basic concerns," said Lopez, a professor of the practice in the KU School of Business and a senior scientist for Gallup. "But our research shows otherwise. We find that emotions matter to everywhere, and perhaps most surprisingly, that the link between and health is even stronger in low-GDP countries. This has important implications for anyone involved in outcomes, including policymakers, health care providers and individuals, no matter what country they're in."

Lopez' describes his research in a new article titled "Is the Emotion-Health Connection a 'First-World Problem'?" The article appears in the latest edition of Psychological Science.

In his study, Lopez examines Gallup World Poll data from more than 150,000 individuals spanning 142 countries, representative of 95 percent of the world's population. The survey asked respondents about their emotions, health, hunger, shelter and threats to safety. Both positive and negative emotions exhibited unique effects on self-reported health, and together, they accounted for 46.1 percent of the variance in self-reported health. These associations were stronger than the relative impact of hunger, homelessness and threats to safety.

Additionally, while both positive and negative emotions were tied to health, positive emotions in particular were found to be more impactful on health in low-GDP countries than in higher-GDP countries.

"Again, this really runs counter to what many people have assumed," Lopez said. "As surprising as it may sound, emotions matter more to health than things like hunger, homelessness and safety, and the relationship between positive emotion and health actually increases as GDP increases."

So how does Lopez explain these findings? One possibility is that medical interventions downgrade the impact of emotions on health. For example, an unhappy adult with resultant hypertension in an industrialized country can take blood pressure-lowering medication, whereas most third-world citizens cannot.

Regardless of the mechanism, Lopez said, his findings are crucial to anyone associated with health care outcomes – whether policymakers, or individual patients.

"The take-home message is that emotions matter for health, and that's true everywhere on Earth, regardless of how developed or undeveloped a nation may be," he said. "Emotions are not just frivolous byproducts of a good or bad day. They're closely linked to our , and they should be considered by medical researchers in the same way we consider smoking, diet and other health factors. Ultimately, we should all do a better job of living our lives as if our health depends on our daily emotions – because it does."