Inspired by studies about which nations are the happiest, economists at Warwick University in the U.K. performed one of their own, concluding that countries whose population bears the most genetic resemblance to Denmark are the happiest.
Not only does their research make the case for the role of genetics in individuals' well-being, it could also explain why Denmark performs consistently well in studies of international happiness.
"The results were surprising," economics professor Eugenio Proto said. "We found that the greater a nation's genetic distance from Denmark, the lower the reported wellbeing of that nation."
Pronto and his partner Andrew Oswald, also of the economics department, compiled data from numerous international surveys including the World Gallup Poll, which involved a total of 131 nations.
They linked cross-national data on genetic make-up and contentment, resulting in a case for the association between happiness and DNA.
"Our research adjusts for many other influences including Gross Domestic Product, culture, religion and the strength of the welfare state and geography," Pronto added.
They also analyzed research pertaining to a mutation of the gene that ignites the reabsorption of the neurotransmitter serotonin, well known in the scientific community to determine one's mood.
"We looked at existing research which suggested that the long and short variants of this gene are correlated with different probabilities of clinical depression, although this link is still highly debated," Pronto said. "The short version has been associated with higher scores on neuroticism and lower life satisfaction."
Pronto and Oswald found that Denmark and the Netherlands have the lowest percentage of citizens with the short version of the genetic mutation.
In a third and final case for the association between happiness and DNA, the researchers found evidence suggesting it is generational.
Analyzing data on Americans' well-being, they compared it to countries from which participants' ancestors could be traced.
"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," Oswald said.
While researchers say more studies will be necessary, they believe there can be no doubt that genetics could help explain the results of global happiness studies.
"More research in this area is now needed and economists and social scientists may need to pay greater heed to the role of genetic variation across national populations," Oswald said.
