It might seem like the perfect get-out clause for those with a ­roving eye: some people just aren’t built to be faithful. Scientists have found a gene that raises the odds of ­cheating on a partner. They say that when a man or woman with the ‘love rat gene’ has an affair, they receive the same chemical rush as a gambler whose luck has changed or an alcoholic savouring a drink。

　　科学家经研究发现，对于那些常常不能安心在稳定的恋情中的人来说，他们做出的劈腿行为属于“天性使然”。研究者发现劈腿的恋人身上有一种基因，这种基因会使得他们更容易在恋情进行时做出背叛恋人的行为。此外，如果在酒精的作用下，具有这种“偷情基因”的男女更容易“一拍即合”做出劈腿的行为。

　　Researchers quizzed 180 young men and women about their attitude towards relationships and tested them for a gene called DRD4, which affects levels of the brain chemical dopamine. The one quarter or so with the ‘love rat’ version of the gene were more than twice as likely to be unfaithful. And when they did cheat, they had more one-night stands, the journal PLoS ONE reports。

　　美国的研究团队调查了180个年轻的男性与女性，经过详细了解了他们以往的感情史与爱情观之后，对他们做名为 DRD4的基因检测，据悉，这种基因能够影响大脑中多巴胺的含量。研究发现，大约25%的人拥有“偷情基因”，而拥有这种基因的人更容易对伴侣做出不忠的行为、发生一夜情的几率比普通人要高出两倍。

　　Last month, scientists found that the same strain of the DRD4 gene can also make people have more liberal views. Because the genetic variant drives people to seek out ‘novelty’, it can also make people more likely to seek out less conventional political views, the U.S. study found。

　　科学家还发现，“偷情基因”并非只具有负面作用，它还具有一些正面影响呢。据调查，具有这种基因的人更能接受新奇的事物，包容性更强。如果对于政治家来说，具有这种基因的政治家往往属于革新派、改革派类别。

　　Vocabulary：

　　roving adj. 流动的；徘徊的

　　dopamine n. 多巴胺(一种治脑神经病的药物)

　　variant adj. 不同的；多样的

　　novelty n. 新奇；新奇的事物；新颖小巧而廉价的物品