Glass Half Full? It's In Your Genes

Main Category: Genetics
Also Included In: Psychology / Psychiatry;  Anxiety / Stress;  Depression
Article Date: 27 Feb 2009 - 1:00 PDT

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Why do some people always look on the bright side of life when others seem to focus on the negatives? According to new research, it could be down to their genes. The findings, published in the Royal Society journal Proceedings of the Royal Society B, help to explain why some people respond better to stress than others and why some are more prone to emotional disorders such as depression.

A team of scientists led by Professor Elaine Fox from the University of Essex decided to tackle the question of why some people have a more positive outlook by taking a closer look at a gene which is already linked to emotional disorders. The serotonin transporter gene is already widely known to impact on brain release of the chemical serotonin which is involved in mood and well-being.

The researchers showed pairs of images to around 100 healthy individuals. Each pair contained a neutral image and either a positive or a negative one. The scientists monitored where the subjects' attention was drawn to when they were shown the images, as well as doing a DNA test looking specifically at the serotonin transporter gene.

Everybody has one of three combinations of this gene either two short versions (SS), two long versions (LL) or one of each (SL). The results demonstrated that individuals with two long versions were much more attentive to positive material and had an aversion to the negative images. Those in the SL or SS groups were neither drawn to the positive material nor avoided the negative images.

These underlying differences have a large role to play in how people respond to life events, says Fox."This is a key mechanism underlying resilience to general life stress," she says, pointing to the fact that the absence of this protection in the SL and SS groups leaves them more susceptible to anxiety and depression.

Previous studies indicated this bias in psychiatric patients but this is the first study to look at healthy members of the population.

The Royal Society