Therapist explains 'Rebecca Syndrome' which more than half of people suffer from and it's bad news for their partners

A therapist has weighed in on the concept of 'Rebecca Syndrome' in romantic relationships - and it's not good news for the partners involved.

Have you ever started dating and found yourself feeling a twinge of jealously when your scroll through your hook-up's social media and see photos of them with their ex? Or perhaps you feel the familiar green mist descending when your partner talks fondly about a memory which occurred during an old relationship.

If you've ever felt like this, you wouldn't be alone.

What is 'Rebecca Syndrome'?

Given the continuous merry-go-round of dating and relationship terms which are constantly cropping up all over the internet, you'd be forgiven for not understanding what Rebecca Syndrome is.

Also known as retroactive jealousy, Rebecca Syndrome is where someone exhibits signs of pathological envy towards their partner's ex-lover.

The circumstances and the specifics of their relationship - or how they came to break up - may not matter; it's the thought that someone else enjoyed special and intimate moments with your person, and that makes you feel jealous.

You could even argue that retroactive jealousy is now a bigger issue than ever thanks to the invention of social media, with a 2017 study from Superdrug revealing just how often people will look up their partner's ex online.

Around 66.7 percent of participants in relationships admitted to searching up a loved one's ex, a figure which drops to 65.8 percent in married couples.

The term 'Rebecca syndrome' comes from Daphne du Maurier's 1938 novel Rebecca (Getty Stock Images)

So why does Rebecca Syndrome occur, and how significant of an impact is it having on people's relationships?

According to psychotherapist Toby Ingham, who has written a book on the subject, the root of retroactive jealousy can be traced back to our upbringing and issues within our families.

"What surprises me is how little linking up we do between what’s happened to us and how we feel about ourselves," he explained during an interview with Vice.

"There are things they’ve been through, things they already knew, but they just haven’t linked that up with what it’s like to be an adult dating in an adult world," he continued.

"The label can give you a place to start, but after that, I think looking at it with greater depth is helpful."

The book was later adapted into a film starring Lily James (Netflix)

Ingham also agrees that retroactive jealousy can be made worse by modern social media, as it's now easier than ever to be present in an ex's life.

"I think the digital age has accelerated a whole set of psychological problems," he added.

This view is shared by Jacqui Gabb, PhD, a professor of sociology and intimacy at The Open University, who told Women's Health: "There’s almost an intensification of retroactive jealousy because there’s a greater capacity for exes to be present in your life through social media, even if you’re not close friends with them anymore."