Why you should not date a beautiful girl!

London: If you are dating a beautiful girl, please take note: Relationships in which the woman is more attractive than the man may be doomed to failure, says a new study.

However, having a handsome husband or boyfriend is no barrier to the couple's success, according to the study.

A team from the Stirling, Chester and Liverpool University in the UK spotted the strange phenomenon while studying whether people tend to pair up with those who are similarly attractive to themselves.

The findings could help explain why Angelina Jolie's marriages to actors Jonny Lee Miller and Billy Bob Thornton ended in just three years, while her relationship with Brad Pitt -- one of the world's most handsome celebrities – has already lasted six years, the Daily Mail reported.

For the study, the researchers took photos of the men and women in more than 100 couples. Some had been together for just a few months, others for several years. The individual men and women were then rated on their looks.

Their analysis revealed that having an attractive husband or boyfriend was no barrier to a relationship succeeding. But, if the woman was extremely beautiful, the relationships tended to last only a matter of months, the researchers found.

Researcher Rob Burriss said: "This would indicate it is the woman who is in control of whether the relationship continues."

"Beautiful women may realise they can afford to pick and choose," he suggested, adding that they may also have the confidence to leave behind relationships that have run their course.

"Attractive women might generally prefer short-term relationships. They're better placed to move on," he said. It is also possible that the relationships end due to jealous behaviour from the woman's less photogenic partner.

Conversely, the less attractive women "may have to make do with what they have, hence the longer relationships", noted Dr Burriss.

The study also found that people tend to pair up with people whose facial features have a similar level of symmetry -- a sign of beauty -- to our own.

"Are all men trying to go out with Anne Hathaway or Angelina Jolie, or do you really wanted to be with someone at the same level of attractiveness as yourself? These findings suggest our ideal partner is one on our own kind of level," Dr Burriss concluded.

The new study was published in the journal Personality and Social Psychology Bulletin.