Why is it some folks just seem happy with life in general, always ready with a smile, yet others never seem to experience that same level of inner contentment?
Is there a special “thing” that makes us happy?
Is it something we are born with, or is it purely our environment, personality and a dollop of good luck?
The answer is it’s a mixture.
It seems that our personality and happiness is determined in part by what we inherit from our parents.
Scientists have been exploring for the possibility of a happiness gene for some time and previous studies suggested that genes contribute up to 50% of our happiness quota based on twin studies.
One gene 5-HTT had been previously looked at because it is known to have a direct role in recycling serotonin, the neurotransmitter known to be involved in mood and depression.
Researchers from the London School of Economics looked at 2500 people as part of The Longitudinal Study of Adolescent Health and looked at the variants of this gene and correlated it to reported life satisfaction in adolescents.
5-HTT has two variants, either a long allele or a short one. We inherit one from each of our parents so we could end up with two long or two short or one of each.
The longer variant (or allele) apparently works better, has a greater number of serotonin receptors in the cell membrane and more gene expression.
The findings showed that people with the long/long combination were likely to report greater life satisfaction, than those who carried the two short variants.
Does this explain why some people appear just to have been “born happy” and why some are less so?
It would be far too simplistic to say that one gene alone is the main contributor to our state of happiness as it is likely to be combination of other genes as well as environmental factors.
The lead researcher Jan-Emmanuel De Neve reported that:
“It has long been suspected that this gene plays a role in mental health, but this is the first study that shows that it is instrumental in shaping individual happiness levels”
There is no single ”happiness gene”. Instead, there is likely to be a set of genes whose expression, in combination with environmental factors, influences subjective well-being.”
So what does this all mean?
Does it make a difference for our overall happiness to know whether we have the longer 5-HTT variants or not?
What this study indicates, is that this one gene does have a role in contributing towards what we call “happiness” and confirms that genetics plays a part overall. Whether we carry the long or short variants makes little difference and can certainly not be used to determine how happy we will be in our lives.
De Neve, J.-E. (2011). “Functional polymorphism (5-HTTLPR) in the serotonin transporter gene is associated with subjective well-being: evidence from a US nationally representative sample.” J Hum Genet.