09 May 2011
ByAppeared in BioNews 606
British scientists say they have discovered a link between an individual's satisfaction with life and the type of 5-HTT (5-hydroxytryptamine) gene they carry. The 5-HTT gene encodes a transporter for the brain chemical serotonin (5HT), which has previously been associated with regulating mood. Individuals carrying the long version of the gene were shown to have a happier outlook compared to those carrying the shorter version of the gene.
'It has long been suspected that this gene plays a role in mental health but this is the first study to show that it is instrumental in shaping our individual happiness levels…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 make-up', said behavioural economist Jan-Emmanuel De Neve of the London School of Economics, who led the study.
Serotonin levels in the brain are thought to be related to the feeling of happiness, with low levels being associated with depression. The serotonin transporter, encoded by the 5-HTT gene, affects the levels of serotonin in the brain. The longer version of the 5-HTT gene results in more efficient transport of this brain chemical. In a previous study led by Professor Elaine Fox at the University of Essex, people carrying the long version of the 5-HTT gene were shown to subconsciously select positive images over negative images.
This latest study goes further in claiming that individuals carrying the long version of the 5-HTT gene also feel more satisfied with life in general. Researchers surveyed 2,574 Americans, aged in their twenties, on how satisfied they were with life. They then tested their DNA for the 5-HTT gene. Sixty-nine percent of individuals who had inherited two copies of the long version of the 5-HTT gene stated they were satisfied or very satisfied with their lives, compared to only 38 percent who had instead inherited two copies of the short version of gene.
'The results of our study suggest a strong link between happiness and this functional variation in the 5-HTT gene. Of course, our well being isn't determined by this one gene – other genes and especially experience throughout the course of life will continue to explain the majority of variation in individual happiness', stated De Neve.
This work may prove helpful in understanding and combating mood disorders. Professor Ed Diener, psychologist at the University of Illinois, said: 'This exciting work offers insights that one day may help us counter disorders such as depression'.
This study was published in the Journal of Human Genetics.