比起陌生人 你和朋友的基因要更相似!

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

提到友誼，有一些共同點是很重要的。

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.

雖然喜歡同樣的電影、在餐館中有相似的品味似乎是很重要的，但實際上對堅固友誼的檢測可能在於你的基因。

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

《美國國家科學院院刊》上發表的一項新研究稱，這是因爲與陌生人相比，朋友之間的基因更相似。

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.

斯坦福大學、杜克大學和威斯康辛大學的一組研究人員，利用來自於《青少年至成人健康國家縱向研究》的數據，對5500名美國青少年展開了調查。

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

在對幾對朋友進行了一系列基因比較之後，研究人員發現他們之間有很大程度的基因相似性，這遠遠超過了陌生人間的相似性。

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

據《時代週刊》報道，研究人員還發現，朋友之間的基因相似度平均是夫妻之間相似度的三分之二。

This might be because people are drawn 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.

這可能是因爲人們容易被那些與他們有共同特徵（相似的背景、受教育程度、相似的身高或體重）的人吸引。研究人員將此稱爲社會同質性。

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.

另一種解釋是，人們傾向於在共同的社會環境中建立友誼。例如，他們可能就讀同一所學校或住在同一個社區。作者寫道，這就是所謂的社會結構化。

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

他們還表示，社會同質性和社會結構化不一定相互排斥，兩者也可能互爲補充。

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

該研究的第一作者、斯坦福大學教授本傑明·多明格在接受《時代週刊》採訪時表示，社會結構化可能更具潛意識性，可能在解釋朋友之間的基因相似性上更有影響力。