Happy person/Adobe Images

Ever wonder why some people always seem to be so damn happy? Well, researchers at the London School of Economics believe a person’s happiness is strongly linked to the 5-HTT gene, which is located on chromosome #17 and regulates the transport of serotonin in the brain.

We are born with two versions of the 5-HTT gene, passed down from each parent. We can inherit long or short versions, and our general happiness may depend in part on the luck of the draw.

Scientists have suspected that this particular gene played a role in mental health, but the London researchers say “this is the first study to show that it is instrumental in shaping our individual happiness levels.”

They analyzed genetic information from more than 2,500 people participating in the National Longitudinal Study of Adolescent Health.  In addition, they asked participants to answer the question,  “How satisfied are you with your life as a whole?” They could answer “very satisfied, satisfied, very dissatisfied, dissatisfied, or neither.”  The researchers compared each participant’s genotype with his/her answer.

They discovered that the happiest study participants had inherited two “long” versions of the 5-HTT gene. The unhappiest had two “short” versions of the gene.

Specifically, they found that

  • 35% with two long versions were very satisfied with their lives
  • 34% with two long versions were satisfied with their lives
  • 19% with two short versions were very dissatisfied with their lives
  • 19% with two short versions were dissatisfied with their lives

Behavioral economist and lead researcher Jan-Emmanuel De Neve says “This finding helps to explain why we each have a unique baseline level of happiness and why some people tend to be naturally happier than others, and that’s in no small part due to our individual genetic makeup.”

But one’s happiness or lack thereof is not determined entirely by the 5-HTT, or so-called happiness gene. In a TED talk on the link between genetics and happiness that De Neve delivered on March 18, 2011, he stressed that other genes are also involved and that while their role may be important, “your experience throughout the course of your life will remain the dominant force in your happiness.”