Monday, October 17, 2011

The Genetics of Happiness: Transporter of Delight

What determines happiness? Many things to be sure, but you might be surprised how much of a role your genes play in shaping your life's satisfaction. A recent article in the Economist details a groundbreaking discovery made about the nature of human happiness. 

Recent years have seen an upsurge in the study of happiness, not simply among geneticists, but also among economists and policymakers. Riding the research trend, a group of scientists from University College, London, Harvard Medical School, the University of California, San Diego, and the University of Zurich examined over 1,000 pairs of twins (fraternal and identical) in an effort to discover the extent to which happiness is associated with DNA. Previous research has used twin studies such as this one to prove the heritability of personality and intelligence. And as it turns out-happiness is also genetic.
The working paper published by the University of Zurich’s Institute for Empirical Research in Economics, “Genes, Economics and Happiness” (found here), has concluded that approximately one third (33%) of the variation in happiness can be attributed to genes.

In addition to conducting the twin study and a genetic association study to determine the influence of genetic variation, the research team took their project a step further. Comparing their results with two previous independent data analyses, they found that those with a transcriptionally more efficient (or longer) version of the serotonin* transporter encoding gene SLC6A4 tend to report significantly higher levels of life satisfaction.

These finds are interesting in themselves, but even more so given its racial implications. All participants in the studies were Americans, but their responses were also broken down by race. The results illuminated the following: White Americans are happier than Black Americans, Asian Americans, and even Hispanics. Interesting or somewhat depressingly predictable? Those with mixed heritage were not included in the results of the study.

However, the report is adamant in its declaration that SLC6A4 does not necessarily “determine” happiness, and that other genes most likely also play a role. The SLC6A4 gene itself only explains less than one percent of the variation in life satisfaction, though all genes together account for a third of total variance. Summarily, there is no one “happiness gene”, and genetic factors in general simply complement, rather than replace the influence of socio-demographic, economic and cultural factors on happiness.

Despite its limitations, the study is groundbreaking in that it is the first to identify a specific gene linked with happiness. Its larger point is well taken- that genes do matter in terms of subjective well-being (which may be a bit of an obvious conclusion). It would be interesting to see research exploring the influence of environmental factors on the relationship between 5-HTTLPR and life satisfaction, as well as research identifying other genes implicated with happiness. 

Bouchez, Colette. "Serotonin and Depression: 9 Questions and Answers." WebMD. Web. 17 Oct. 2011. <>.

De Neve, Jan-Emmanuel, Nicholas A. Christakis, James H. Fowler, and Bruno S. Frey.Genes, Economics, and Happines. Working paper. National Institute on Aging, National Science Foundation, 20 Sept. 2011. Web. 17 Oct. 2011. <>.

"The Genetics of Happiness: Transporter of Delight." The Economist. 15 Oct. 2011. Web. 17 Oct. 2011. <>.

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