When you're in love with a beautiful woman, you really do have to watch your friends.

Just like Dr Hook warned in their 1979 hit, When You're In Love With A Beautiful Woman, research has revealed that relationships in which the woman is more attractive than the man may be doomed to failure.

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

The phenomenon was spotted by British researchers who were studying whether it is true that we tend to pair up with those who are similarly attractive to ourselves.

Their findings could help explain why Angelina Jolie's marriages to actors Jonny Lee Miller and Billy Bob Thornton barely lasted three years a piece.

In contrast, her relationship with Brad Pitt, one of the world's most handsome celebrities, has already lasted six years, suggesting she has found her match.

The Stirling, Chester and Liverpool university 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.

The analysis revealed having an attractive husband or boyfriend was no barrier to a relationship succeeding. But, if it was the woman who was the one blessed with good looks, the relationships tended to last only a matter of months, the journal Personality and Social Psychology Bulletin reports.

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

Beautiful women may realize they can afford to pick and choose, he suggests. 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."

It is also possible the relationships end due to jealous behavior 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", he said.

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

Dr Burriss said: "Are all men trying to go out with Anne Hathaway or Angelina Jolie, or do you really want 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."

女友很漂亮？防着哥们儿朋友。

正如虎克博士1979年的热曲《当你与美女相恋》，研究发现如果是美女配丑男，感情则难以持久。然而如果帅哥配丑女，则不会对二人的感情有障碍。

英国的研究者们对此现象进行了研究，以明确我们是否习惯于和我们长相差不多的人恋爱交往。研究结果可以用来解释为何安吉丽娜•朱莉和前两任男友强尼•李•米勒和比利•鲍伯•桑顿的婚姻均只维持了三年。

然而，她和当今级帅哥布拉德•皮特的感情却已经持续了六年，因她终于找到了和自己长相匹配的人。

斯特灵大学、切斯特大学和利物浦大学的研究者们对100多对情侣夫妇拍了照片，并分别对每一个人的长相进行了评分。这些情侣、夫妇有的在一起刚几个月，有的已长达数年

《人格心理学与社会心理学期刊》报道称，分析结果表明男性若很英俊不会对关系发展带来障碍，但是女性若太漂亮，感情仅能维持几个月时间。

研究员罗伯•布里斯称：“这表明关系的持续或中断均是由女性决定的。”

他说美女或许知道自己的选择空间大，而且有终止关系的自信心。

“美女一般喜欢短期感情，也更容易接受新的感情。”

当然，关系终结也可能是由于美女的男友或丈夫太过嫉妒。

他说，与之相反，长相平凡的女性“能够充分利用珍惜自己的所有，感情因而也更为持久”。

此研究也发现人们更倾向于选择那些与自己的相貌对称水平（美貌的指标之一）相近的人。

布里斯博士说：“男性是都想与安妮•海瑟薇或安吉丽娜•朱莉这样的美女约会，还是想着自己长相相当的人共处？这些研究结果表明我们的理想对象就是那些与己相貌相当的人。”