Many of us may have lists of contacts and followers on social media networks that extend into the thousands, but new research has found we may actually only have five real friends. 我们中的许多人通讯录里的联系人和社交媒体网络上的好友可以增加到数千人，但是新研究指出，事实上我们拥有的真正意义上的朋友可能只有5个。

A team of scientists have found that while humans have the capacity to form complex layered societies, we face an upper limit to how many friends we can have in our inner circle. 一个科学家团队发现，人们可以构建纷繁复杂、层次分明的社会群体，而在自己的社交圈里，我们拥有的朋友数量是有上限的。

They say this upper limit of five has likely gone unchanged for hundreds of thousands of years and probably governed social relationships when humans lived as groups of hunters. 他们表示，几十万年来，5个朋友的上限可能从未改变，或许从人类集体狩猎开始，这种模式一直掌控着人际关系。

Whenever we add someone new to our social network, they argue, each new friend is actually slightly more distant than those of the inner circle. 他们认为，无论我们在什么时候从社交网络上添加新朋友，每位新朋友还是比我们圈子里的朋友要稍微有距离些。

It suggests that while we may have just a few friends, we can still surround ourselves with acquaintances. 这表明了我们可能只有几个朋友，但周围却围绕着一群熟人。

Michael Harré and Mikhail Prokopenko, both with the University of Sydney in Australia, said while we may only have five close friends, our social network from them can extend to 132 people. 来自悉尼大学的迈克尔•哈雷和米哈伊尔•普罗科彭科表示，虽然我们只拥有5个亲密朋友，但是我们可以通过他们把自己的社交网络扩展至132人。

The researchers built computer models to analyse human social networks and then compared them to hunter-gatherer societies. 研究者创建了电脑模型来分析人类社交网络，接着将分析出来的数据同采集狩猎社群进行对比。

They explain that from an evolutionary perspective, it was important to have small groups of close-knit social connections when humans were on hunting expeditions and other dangerous stations. 他们从进化的角度解释道，处在狩猎探险或其他危险情况下，拥有紧密社会联系的小团体对人类而言是至关重要的。

This would mean that we did not have to be as close with the rest of the wider group - as long as we had a strong bond with around 5 others. 这意味着只要我们和5个朋友关系亲密，就无需与更多的人保持紧密联系。

Even now, as we add or follow others on social media, most new connections are made through meeting friends of others. 即使现在我们会在社交媒体上添加或关注其他人，但大部分人还是通过与其他人的朋友见面形成新的联系。

Writing in the Journal of the Royal Society Interface, the researchers said: conclude that humans were probably egalitarian in hunter–gatherer-like societies, maintaining an average maximum of four or five social links connecting all members in a largest social network of around 132 people.' 研究者在《英国皇家学会界面杂志》上写到：我们得到的结论是处在狩猎采集者之类的社会团体中，人类可能会主张平等主义，他们会保持人均4到5个的社会联系人，把这些联系人整合起来，我们最多能将社交网络关系扩展至132人左右。

As we form new connections and relationships, they become increasingly distant from our 'core' starting group 当我们构建新型连接与关系时，这些人离我们最初的核心团体越来越远。

The researchers added that the 'social brain hypothesis' describes 'neurologically constrained capacity for maintaining long-term stable relationships'. 研究者补充道，“社会化大脑假说”描述的是维持长期稳定关系的神经控制能力。

The 'hunter-gatherer' example shows how social hierarchies can form - you only need to directly know a few people in a large group in order to become a leader figure. “狩猎者采集者”的例子证明了社会阶层是如何形成的，要成为领导者，你只需直接了解大团体中的几个人便可。

The researchers say that while social media is changing the number of people we can be connected to - in 2014, the mean average number of Facebook friends was 338 - it is unlikely to change the number of friends we actually have. 2014年，脸书用户的平均朋友数是338人。研究者表示，虽然社交媒体正在改变我们联系人的数量，但这不太可能会对我们实际拥有的朋友数造成影响。