Despite the fairytales, princesses tend to marry princes, not frogs.

Once, I fell for a man I thought was perfect for me. He was 20 years older, loved dogs, hated parties and was obsessed with his steel guitar.

It didn’t matter that I’m a cat girl, make Paris Hilton look a bit anti-social and the nearest I’ve ever come to musicianship was playing Little Donkey on a squeaky recorder - I thought he was my soulmate.

It took us about a fortnight to realise we found each other incredibly irritating.

I discovered the hard way that, while opposites attract, they don’t necessarily have a rosy future together. Because despite people’s conviction that it takes two very different halves to make a whole, evidence consistently suggests the happiest long-term relationships are based on similarity.

So perhaps it’s no surprise I’m now married to a man I met at work, who grew up in the next town, shares my love of charity shops, thrillers and Mad Men, has the same values and beliefs and, like me, finds “funny cats” videos amusing.

A major study from the University of California found that single people are drawn to potential partners whose looks and desirability are on a par with their own - which may explain why Brad and Angelina have made it so far, and why “she’s out of my league” is a genuine reason not to bother. We are also unlikely to pick a long-term partner if they’re from a very different socio-economic background - which scuppers the premise of most fairytales. In real life, the Prince would have dumped Cinderella for a duchess.

Popularity is also a big indicator of compatibility - with socialites being instantly attracted to others with lots of friends.

Relationship psychologist Paula Hall agrees that, when it comes to basic life choices and attitudes, dating your polar opposite is a tough call. “Honesty levels, wanting children, spiritual beliefs and basic relationship ground rules are all crucial,” she says. “If you don’t agree on these, the relationship may not succeed.

“But one reason we’re attracted to our opposite is that we see qualities in them we want for ourselves, such as calmness or sociability.”

So maybe deep down I’d like to be a dog-loving steel guitar player in late middle age. Actually, it’s not unappealing - but, as I swiftly learnt, I don’t want to live with one.

Despite the fairytales, princesses tend to marry princes, not frogs. I suspect we’ve been conned by a raft of romantic novels and films into believing the only relationship worth having is one that requires constant struggle.

Would Jane Eyre have been quite so romantic if she’d muttered “that Edward Rochester”s a grumpy so-and-so”, and stuck with the man who was really right for her, the kindly Christian missionary?

Would Pride And Prejudice have captured women’s imaginations for 200 years if Elizabeth Bennet had realised Darcy’s anti-social glumness was the last thing she needed?

Opposites may attract - and often do. But on the evidence available, there’s no way they should turn their brief, misguided passion into a long-term relationship. - Daily Mail