When it comes to friendships, it's important to have some things in common.

提到友谊，有一些共同点是很重要的。

However, while enjoying the same films and having similar taste in restaurants might seem important, the real test of a strong friendship could lie in your genetics.

虽然喜欢同样的电影、在餐馆中有相似的品味似乎是很重要的，但实际上对坚固友谊的检测可能在于你的基因。

This is because friends are more genetically² similar than strangers, claims a new study published in Proceedings³ of the National Academy of Sciences.

美国国家科学院院刊》上发表的一项新研究称，这是因为与陌生人相比，朋友之间的基因更相似。

A team of researchers from Stanford, Duke and the University of Wisconsin examined 5,500 American adolescents using data from the National Longitudinal Study of Adolescent to Adult Health.

斯坦福大学、杜克大学和威斯康辛大学的一组研究人员，利用来自于《青少年至成人健康国家纵向研究》的数据，对5500名美国青少年展开了调查。

After carrying out a series of genetic¹ comparisons between pairs of friends, they found a slew⁴ of genetic similarities between them, far more than between pairs who didn't know each other.

在对几对朋友进行了一系列基因比较之后，研究人员发现他们之间有很大程度的基因相似性，这远远超过了陌生人间的相似性。

They also found that friends were on average around two-thirds as genetically similar as married couples, reports Time.

据《时代周刊》报道，研究人员还发现，朋友之间的基因相似度平均是夫妻之间相似度的三分之二。

This might be because people are drawn⁵ to those with whom they have shared characteristics i.e. having similar backgrounds, levels of education or being of a similar height and/or weight. The researchers describe this process as social homophily.

这可能是因为人们容易被那些与他们有共同特征（相似的背景、受教育程度、相似的身高或体重）的人吸引。研究人员将此称为社会同质性。

Another explanation they suggest is that people tend to form friendships within shared social environments. For example, they may attend the same school or live in the same community. This is known as social structuring, the authors write.

另一种解释是，人们倾向于在共同的社会环境中建立友谊。例如，他们可能就读同一所学校或住在同一个社区。作者写道，这就是所谓的社会结构化。

They added that social homophily and social structuring are not necessarily mutually exclusive processes and that the two may also complement⁶ one another.

他们还表示，社会同质性和社会结构化不一定相互排斥，两者也可能互为补充。

Speaking to Time, lead author and Stanford professor Benjamin Domingue concluded that the latter, which might be more subconscious⁷, could be more influential⁸ in terms of friends sharing similar genetics.

该研究的第一作者、斯坦福大学教授本杰明·多明格在接受《时代周刊》采访时表示，社会结构化可能更具潜意识性，可能在解释朋友之间的基因相似性上更有影响力。