Teen survey reveals gene for happiness

• 00:01 06 May 2011 by Andy Coghlan
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Forget money, fame and good looks. The best chance of happiness and contentment comes from having two copies of a particular gene.

That's true, at least, for 2574 ageing adolescents in the US who answered a questionnaire about their satisfaction with life, or lack of it.

"It's the first formal finding of a happiness gene, although I'm sure others will be found," says Jan-Emmanuel De Neve of the London School of Economics, and co-author of the study.

The happiest people tended to have a long variant of a gene called 5-HTTLPR. This gene makes a transporter molecule for serotonin, a chemical that brain cells use to communicate with each other, and the long variant helps to recycle serotonin faster and more efficiently than the short one.

Teen genes

De Neve extracted his data from the US National Longitudinal Study of Adolescent Health, which has been following the same set of adolescents for 13 years, from 1995 to 2008. Genomic information in this study allowed him to distinguish respondents who had two long versions of 5-HTTLPR from those who had two short versions, or one of each.

Twice as many respondents with two long versions said they were very satisfied with life compared with carriers of two short versions.

Conversely, 26 per cent of those with two short versions of the gene said they were dissatisfied with life, compared with 20 per cent of people carrying two long variants.

De Neve says it is unclear how the speed of serotonin recycling affects mood, but it clearly does. "The more efficient version appears to influence predisposition towards happiness," he says.

More to come

De Neve says he has already replicated the results in another large study that is in press at the journal Econonometrica. His results also tally with those from a previous study which found that people carrying two long variants were more optimistic.

"There's no doubt that the evidence is growing that the serotonin transporter is involved in varying levels of emotional vulnerability and well-being," says Elaine Fox of the University of Essex in Colchester, UK, who led the optimism study.

De Neve stresses, however, that many other factors play into how happy we feel with our lot. "There's no way you should interpret these gene results as deterministic," he says. "If you're very unlucky throughout your life, losing your job or close relatives, it will be a more important source of unhappiness than any particular genes you carry," he says.