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.

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Researchers in Beijing say some people are born with a 'singleton gene' that makes them bad at relationships (stock image shown). Those with it are 20 per cent more likely to be single than others

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.

ARE WOMEN BEING HELD BACK BY THEIR HUSBANDS? Women are increasingly putting their husband's career before their own, a controversial separate study of Harvard Business School graduates has found. It canvassed more than 25,000 male and female students, and found 40 per cent of Generation X and 'boomer' women said their spouses' careers took priority over theirs. The researchers also said only about 20 per cent of them had planned on their careers taking a back seat when they graduated. They concluded that while women had good intentions when they graduated, they ultimately ended up being held back by their partners. Advertisement

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.

Writing in the journal Scientific Reports, the researchers said: ‘As pessimism and neuroticism are detrimental to the formation, quality and stability of relationships, this connection between the G allele and psychological disorders might decrease carriers’ dating opportunities or lead to romantic relationship failure.’

The researchers said that students may have more free time and freedom to form relationships than others.

And at other times of life, other factors, such as pressure from parents to marry, may be much more influential.

Despite this, they concluded that their study provides ‘evidence for genetic contribution to social relationships in certain contexts’.

Other scientists said that while genes will inevitably influence relationships, their role in most cases will be small.

Hair samples from almost 600 Chinese students were tested by scientists. Those with the ‘G’ version of the 5-HTA1 gene were much more likely to be single than those with the ‘C’ version. It suggests some people struggle to date and maintain relationships (stock image shown) than others

Dr Pam Spurr, a relationship expert, said that we don’t have to let our genes rule our lives.

She said: ‘I know that our genetic heritage determines some of our behaviour but we always have choice.

‘If someone’s difficulties with dating are flagged up to them, I believe they can learn to interact in a way that will make them more successful in meeting somebody.

‘I feel quite optimistic about that.’

Professor Tim Spector, an expert in the role of genes from King’s College London, questioned how strong the research was.

However, studies show that our odds of getting married and staying married and our number of sexual partners are all influenced by our DNA.

Despite this, genes are not the be all and end all. Simple evidence for this comes from looking at identical twins.