Economists at the University of Warwick's Centre for Competitive Advantage in the Global Economy (CAGE) studying world happiness rankings have concluded that there is a correlation between people who have Danish genes and a higher level of happiness.
Denmark frequently tops the charts when it comes to being the happiest country in the world, so the researchers decided to look at whether there was a link between the genetic makeup of people and a nation's happiness.
To do this, they analysed data on 131 countries, provided by international surveys such as the Gallup World Poll, World Value Survey and the European Quality of Life Surveys.
"The results were surprising, we found that the greater a nation's genetic distance from Denmark, the lower the reported wellbeing of that nation. Our research adjusts for many other influences including Gross Domestic Product, culture, religion and the strength of the welfare state and geography," said Dr Eugenio Proto.
Their open-access paper, entitled National Happiness and Genetic Distance: A Cautious Exploration is published on the Institute for the Study of Labour (IZA) website.
Existing research has suggested that a particular mutation of ABCB1, a gene that influences a person's reuptake of serotonin, a chemical that is linked to moods in the brain.
"We looked at existing research which suggested that the long and short variants of this gene are correlated with different probabilities of clinical depression," said Dr Proto.
"The short version has been associated with higher scores on neuroticism and lower life satisfaction. Intriguingly, among the 30 nations included in the study, it is Denmark and the Netherlands that appear to have the lowest percentage of people with this short version."
Finally, the researchers analysed Americans and looked at which part of the world their ancestors had come from.
"The evidence revealed that there is an unexplained positive correlation between the happiness today of some nations and the observed happiness of Americans whose ancestors came from these nations, even after controlling for personal income and religion," said Professor Andrew Oswald.
"This study has used three kinds of evidence and, contrary to our own assumptions when we began the project, it seems there are reasons to believe that genetic patterns may help researchers to understand international well-being levels."
The researchers say that further studies need to be done, and social scientists may need to start paying more attention to the role of genetic variation across national populations.