If it seems you are permanently single while everyone else around you is in a relationship, blame your DNA.
Scientists have identified a ‘singleton gene’, and found that those who have it are 20 per cent more likely to be single than others.
It is thought that by lowering levels of the feel-good brain chemical serotonin, the gene makes people less comfortable in close relationships.
This could make it harder to form them in the first place – or lead to break-up after break-up.
The scientists from Peking University in Beijing tested hair samples from almost 600 Chinese university students to analyse a gene called 5-HTA1, which comes in two different versions.
Those with the ‘G’ version were much more likely to be single than those with the ‘C’ version.
Some 60 per cent were not in a relationship – compared to 50 per cent of those in the c group.
Importantly, the link couldn’t be explained by other factors that influence relationships, including appearance and wealth.
The key to the findings seems to be the role of the 5-HTA1 gene in the brain.
Those with the ‘G’, or singleton, version make less serotonin, a brain chemical involved in mood and happiness.
It was already known that people with the ‘G’ allele, or version, find it more difficult to get close to others.
Plus, they are more likely to be neurotic and to suffer from depression.