Unless you’ve had a really nasty, bitter break-up – the type that makes your friends spit blood and your mum start plotting violent revenge – it’s often tempting to try and stay friends with an ex. It seems like the healthiest, most mature option, doesn’t it? If you don’t genuinely think they’re the spawn of Satan, there seems no reason to completely cut them out of your life.

And in the age of constant digital connection, where we’re used to reading updates on the lives of people we haven’t seen for years (“No way, Kirsty and Chris D from school are together now?!”) unfollowing an ex on social media is a big, bold statement. It either says, “I have literally zero interest in how your life unfolds” – or, “I am so interested in how your life unfolds that I have to remove the temptation to cyber-stalk you every minute of the livelong day”. If you’re trying to take the high road, neither seems a great option.

But psychological research suggests that not pressing “delete” on past relationships can seriously affect our ability to recover from a break-up.

A British study published in the journal Cyberpsychology, Behavior and Social Networking found that about one in three people admitted to “Facebook stalking” an ex-partner at least once a week. It also showed that staying Facebook friends with an ex and monitoring their profile can increase feelings of distress about the relationship ending. This kind of online “surveillance” was associated with lower personal growth, a protracted sense of longing for the ex-partner, as well as more negative feelings and increased sexual desire for the ex. In other words, it can all get a bit messy.

The study shows a correlation, rather than causation, between keeping your ex as a friend Facebook and negative psychological effects. But according to psychologist Dr Tara Marshall of Brunel University, who led the research, the findings still “suggest that exposure to an ex-partner through Facebook may obstruct the process of healing and moving on from a past relationship”.

Dr Marshall has spent the last few years investigating the relationship between social media and romantic psychology. In a recent interview with MIC, she confirms that “all indicators would suggest that [staying online friends with an ex is] not healthy”.

In another study led by Dr Marshall, anxiety in the context of romantic relationships was shown to be strongly associated with “Facebook jealousy and surveillance”.

Dr Marshall advises thinking carefully about why you might really want to stay online “friends” in the first place, and says that people usually have one of two motives. Either they’re genuinely cool with the situation and simply can’t be bothered to unfriend – or they’re using social media as a way of maintaining a sense of connection. “People are often morbidly curious,” she says. If that sounds familiar, it might be time to grit your teeth and unfollow. “The more you can minimise exposure,” says Dr Marshall, “the more space you have to move on.”

While we might grasp that rationally, we might not actually have the nerve to click delete. So in November 2015, Facebook started testing tools to help people reduce the amount they have to see a former partner on their news feed. Now, when people change their relationship status from “in a relationship”, they’ll see a range of tools allowing them to see less of their ex’s name on Facebook – and limit the amount that their ex can see them.