May 6, 2011

Is Happiness Coded Into Our Genes?

Is our general outlook on life DNA coded into us at birth? Researchers at the London School of Economic and Political Science have discovered that those of us with a functional variant of the 5-HTT gene in our DNA tend towards general happiness about life, The Telegraph reports.

The 5-HTT gene comes in long and short versions and is involved with the transport of serotonin, a feel-good chemical in the brain. The longer variant allows more efficient release and recycling of the neurotransmitter that creates a self of well-being.

In a study of more than 2,500 Americans, the variants of the gene influence how satisfied "“ or dissatisfied "“ people were with their life, The Guardian UK is reporting. People born with two of the long versions of the gene were more likely to describe themselves as "very satisfied" with life than those who had the two short versions. One each of the gene is passed from each parent.

The study marks a tentative step towards explaining the mystery of why some people seem naturally happier than others.

"This gives us more insight into the biological mechanisms that influence life satisfaction," said researcher Jan-Emmanuel De Neve, "If you're feeling down, you can say it's your biology telling you life is less rosy that it is," he added.

Genetic coding makes up only one of the many reasons for peoples outlook. Research with twins suggest that genes account for roughly a third to a half of the variation in happiness between people. How many genes it takes to affect how cheerful we are is not yet determined.

The genetic makeup of 2,574 people was researched as representative of the general population by De Neve. Their medical histories were recorded for the US National Longitudinal Study of Adolescent Health.

Among the records were answers to a question participants were asked in their early 20s about life satisfaction. A list of 6 answers could be chosen ranging between "very satisfied" to "very dissatisfied".

De Neve's results, published in the Journal of Human Genetics, describe roughly 40 percent claiming to be "very satisfied" with life, and among these, 35.4 percent had two long variants of the gene and only 19.1 percent had two short versions.

Of those who were "dissatisfied" with life, 26.2 percent had two long variants of the gene, while 20 percent had two short versions, indicating a slight over-representation of the long variants in happier people.

Everything else being equal, De Neve concluded that having one long version of the gene increased the number of people claiming to be "very satisfied" by around 8.5 percent. Having two long versions raised the number by 17.3 percent.

De Neve emphasized however, that having two short versions of the gene did not mean a person was to lead a miserable life any more than two long versions would make someone impervious to a pessimistic outlook.

"This gene has an important influence, but you cannot say it causes happiness. Happiness is hugely complex and your experiences throughout the course of your life will remain the dominant force on that," he said.


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