How lonely we feel, or how often we want to socialise, seems to be partly determined by our genetic coding, new research reveals – and that potentially offers new ways to tackle health problems associated with loneliness.
Drawing on survey responses from 487,647 participants of the UK Biobank scheme, the researchers identified 15 gene regions linked to loneliness.
They also found evidence of a possible association between obesity and feeling lonely, suggesting one might be driving the other – so the same genes could be increasing the likelihood of someone being overweight and being lonely, and tackling them both together might be a better approach.
"We often think that loneliness is driven purely by our surrounding environment and life experiences, but this study demonstrates that genes can also play a role," one of the team, John Perry from the University of Cambridge in the UK, told The Telegraph.
"There is always a complex mix of genes and environment, but it does suggest that at a population level, if we could tackle obesity we would be able to bring down loneliness as well."
Around one in four people over the age of 65 in the UK suffer from loneliness, explain the researchers, which is also linked to an earlier death.
While loneliness has been associated with genetics before, this is the first time researchers have been able to highlight specific gene regions that seem to have an impact on how isolated we feel.
And while this method of using retrospective self-reporting isn't enough to prove cause and effect just yet – there might be other hidden factors involved – the collected data certainly makes a strong case.
Even if the genetic coding identified in the study doesn't fully guarantee or fully rule out feelings of loneliness, it looks like it might tip the scales one way or the other. Around 4-5 percent of our tendency to feel lonely could be inherited, the researchers think.
Participants were also quizzed on what social activities they got up to. The researchers found variations in 13 gene regions linked to whether people preferred to go to the pub, and 6 gene regions linked to preferring the gym. There were also 18 gene regions linked to whether people went to religious groups.
And the team also found genetic overlaps with traits identified in previous studies: depression, obesity, and poor cardiovascular health in particular. It could be that these traits are combining to increase the risk of loneliness in a particular person.
To put it another way, two people in very similar situations might feel differently as to whether they're lonely or not – and this study suggests that could be partially down to the genetic coding they were born with.
The researchers emphasise that a host of genetic and non-genetic factors are likely to be involved, so we absolutely can't say that there's a "loneliness gene" or that your feelings are totally genetic.
But these genetic clues do match up with the way the world works: some of us are perfectly content to live solitary lives, while it can feel like torture for others.
"Our findings highlight the specific genetic basis for social isolation and social interaction," write the researchers. "We find evidence for shared genetic effects across social traits, in addition to more specific pathways that drive engagement in particular activities."
The research has been published in Nature Communications.