Optimism may be in the genes

Whether a person looks on the brighter side of life may be the result of a gene variation, claims a study published last week.

Published in the journal 'Proceedings of the Royal Society B', the study claims that different versions of a particular gene, which affects levels of the mood-altering brain neurotransmitter serotonin, may impact whether we are drawn to positive or negative aspects of life. People with a 'long' version of the gene were found to focus on a sunnier aspect, and those with shorter versions of the gene focussed on the negative. The researchers conducting the study hope that their findings will be used to help develop new treatments for people with anxiety and depression.

DNA samples showing the long or short gene were gathered from 97 volunteers by a group of researchers led by Elaine Fox at the University of Essex. The researchers then carried out what is known as a 'dot-probe paradigm test' to see how the volunteers reacted to various positive, negative and neutral images.

Participants were shown a series of images on a screen, followed by a dot, and asked to say when the dot had appeared. Previous experience performing this kind of test has shown that the more distracting an image is to someone, the longer it will take them to identify the dot on the screen. Fox and her team used this theory to identify what sort of images people found distracting and discovered that participants with the longer gene variant averted their eyes from the negative images and announced the position of the dot more speedily than those with a short gene variant whose eyes lingered over the negative image.

The researchers suggested that their findings indicated a 'genetically driven tendency to look on the bright side of life...underlying general resilience to general life stress'.

The NHS Knowledge Service has raised some queries about the findings in its review of the results; it points out that people's personalities are complex and likely to be affected as much by environmental factors as genetic. It also points out that although the study showed differences in people's tendency to focus on negative or positive images, it did not find differences in levels of depression, anxiety, neuroticism or extroversion, and so no conclusions can be drawn about how the gene might affect these characteristics.