Scientists at Peking University in Beijing, China, found that when their student subjects carried two copies of a gene variant linked to how the neurotransmitter serotonin functions, they were significantly more likely to have a romantic partner.
The 5-HT1A gene codes for a receptor protein that sits on the surface of cells and responds to serotonin. There are two variants of the gene, called C and G. Each person is born with two copies of the gene, and inherits one copy from each parent.
The researchers found that half of the students with two copies the C variant were in a relationship. But only 40 percent of those who inherited just one C or two Gs were romantically attached. In total, the study involved 579 volunteers.
The G variant has previously been associated with anxiety and depression, although researchers are far from agreement as to the extent of the effect involved.
'As pessimism and neuroticism are detrimental to the formation, quality and stability of relationships, this connection between the G and psychological disorders might decrease carriers' dating opportunities or lead to romantic relationship failure,' the paper suggests.
However, some commentators were sceptical of the findings. 'Whilst genetic factors will inevitably influence relationship status, this specific marker accounts for only a very small part of that, and on its own has little bearing on whether an individual is in a relationship or not,' Dr Thalia Eley, professor of developmental behavioural genetics at King's College London, told the Guardian.
'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', she told the paper.
In contrast, talking to The Guardian, Dr Aleksandr Kogan, a lecturer in psychology at the University of Cambridge, called the research 'provocative and really interesting'.
'A lot of things affect whether you're in a relationship or not,' he said. 'People break up under a lot of different circumstances. So you wouldn't expect everyone who [carries two copies of the C variant] to be in a relationship.'
'But 50 percent of them are, compared with only 40 percent of the others, and that's quite a gap.'
The research was published in the journal Scientific Reports.