Flirty text messages cannot beat old-fashioned romance when it comes to a strong relationship, a study suggests.
Student researchers found sending and receiving affectionate texts made no difference to the quality of a relationship.
They said 'no amount' of 'remote presence' compensated for a lack of time together or a lack of affection outside of digital communication.
The research, carried out by Leeds Beckett University over two years, involved 537 people in relationships, most of whom were women in their thirties.
Britons exchange 150 billion texts a year, a number falling only as people turn instead to internet-based services.
While a number of studies have shown that 'affectionate communication' is crucial to a couple's happiness, the impact of digital conversation is poorly understood.
Study author Anna Batho, a psychology Master's student, said: "I think what's so surprising is that it goes against logic.
"You'd think that texting someone lovely things would improve your relationship -but it doesn't work like that.
"It means that all those people who live apart from their partner can't get away with some thoughtful texts.
"It's sad really, that this technology doesn't make a difference. Yes, you're in touch, but it might still not be enough."
The research did not look at tools which are based around video-chats, such as Skype or FaceTime.
This leaves open the possibility there may be a positive effect on relationships when those chatting via text or online can see each other.
The study also notes that although there are now more mobile phones in Britain than people, divorce rates increased by 0.5 per cent from 2011 to 2012 and a third of marriages end within 15 years.