They turn up weekly in my inbox, gnawing away at my soul. The kind words, the smiling faces, the ego-stroking invitations to connect, all of which I guiltily ignore. 它们每个星期在我的邮箱里出现，让我的灵魂饱受折磨，这些友善的文字和笑脸，放低身段以求建立往来的邀请函，我因忽视它们的存在而感到内疚。
The thing is, I buy into the idea of Dunbar's number — that our primate brains limit us to meaningful social contact with no more than about 150 people — and I am already exceeding 200 on LinkedIn.因为我信奉邓巴指数，即作为灵长类动物的大脑限制了我们有效社交人数不超过150人。而我在领英上的好友已经超过了200.
Professor Robin Dunbar, the Oxford university anthropologist who came up with the eponymous figure after noting the strikingly similar sizes of human groupings ranging from Neolithic villages to Roman legions to an average Christmas card list, has posited that our social attention is not distributed evenly among those 150 confidantes but instead layered like an onion;牛津大学的人类学家罗宾.邓巴教授，以他从新石器时代村落到罗马军团，及至一份普通的寄圣诞节卡片的名单中推断出的令人震惊的人类群落规模数据之后，得出了以他名字命名的邓巴指数结论，他推测我们的社交注意力并非均匀的分给这150人，而是像洋葱一样富于层次。
five closest contacts in the innermost layer, then 10 in the next, followed by 35 and 100.具有最亲密关系的内层有5人，之后亲密度次之的一层10人，接下来依次是35人一层和100人一层。
Now a study of mobile phone calls has attempted to test Prof Dunbar's hypothesis about our Russian doll-like shells of emotional intimacy, providing insight into how we stratify our social connections.如今一项对于手机呼叫数据的研究试图以我们俄国美女们的恋爱情况对邓巴教授的推测进行佐证，这项研究就我们如何进行社交对象分层提出了深刻见解。
Along with colleagues at Finland's Aalto University School of Science, Prof Dunbar looked at a 2007 data set of European mobile phone calls, comprising 35m users making a total of 6bn calls.邓巴教授与芬兰阿尔多大学科学院的同事一起研究了一份2007年欧洲移动电话数据，3500万用户总共打出了60亿个电话。
The frequency of calls between two people was a proxy for emotional closeness. Those who made just emergency or business calls were excluded; only those making reciprocal calls to at least 100 people were included.两个人之间电话往来的频率显示了大致的亲密度。那些因公共急救和业务往来而拨打的电话不含在内，只有打给超过100人并与其有往来电话的才计入其中。
By scanning networks of calls and ap-plying clustering algorithms, researchers found people tended to have either four or five layers in their social onion. 通过扫描电话呼叫网络并采用聚类算法，研究者发现人们倾向于拥有一个4层或5层结构的"社交洋葱"。
On average, those with four layers had: four closest confidantes, often relatives, whom they dialled most frequently; 11 in the next layer; then 30 and 129.总体看来，一个4层结构"洋葱"包含: 4个至交，通常是他打电话最多的亲人; 下一层11个，再下一层30个，最后一层129个人。
For those with five layers, the number of friends was split slightly differently: three closest contacts; then 7, 18, 43 and 134. 那些拥有5层"洋葱"的朋友分层的划分稍有不同: 最亲密的有3人，然后依次每层是7人，18人，43人，134人。
The analysis appeared on the arXiv server last month, where scientists can upload results for academic discussion（sometimes, but not always, as a precursor to peer-reviewed publication）.这份 分析报告上个月在"虫洞"服务器上发表，该服务器允许科学家上传学术讨论论文(该平台时不时的发表一些学术先驱的科学预想)
While the idea of social “layering” seems robust according to this analysis, the variations noted suggest that the number of layers corresponds with a social spectrum.尽管根据此项研究而得出关于社交分层的观点看起来有些简单粗暴，对其变化之处的了解则暗示层次的多寡取决于社交范围。
One idea to emerge from the study is that individuals with four layers might be introverts while those with five are extroverts.由此引发的一个观点认为，具有4层结构的个体可能性格较内向，而具有5层结构的个体可能较外向。
The paper has limitations: it looked at just one year of data. Friendships can be impermanent, varying across time and place, and reflecting our lives at particular stages. 该论文的局限性在于它仅依据1年的数据。友谊可以是永恒的，并随着时间和地点的变化而产生变化，反映我们某个特别的生活阶段。
Frequency of contact does not always correlate with depth of relationship; longstanding bonds often do not need intensive tending to bloom.联系的频率并不一定与交往的深度相关; 君子之交淡如水的情况也是有的。
But it is also possible that his study captures a unique picture of friendship: a 2007 data set represents the social world before smartphone ubiquity, and before people routinely began maintaining friendships on Facebook and other online sites on their mobile devices.然而他的研究有可能仅仅抓住了友谊的特殊情形，即2007年的数据反映的是智能手机被广泛使用之前的社交情况，在那之后，人们普遍运用智能手机在Facebook和其他类型的网络社交媒体上维护他们的友谊。
There is also a persuasive consistency in the numbers, the researchers note. This intuitively mirrors real life: even if a house move or a job change forces achange of circumstances, old acquaintances are superseded by new ones.研究者指出以上观点存在数据上的持续性变化作为支持。这直观的反映了现实生活，比如由一次搬家或跳槽引发的环境变化肯定导致朋友圈子的更新换代。
The exact components of the layers may change but the layers themselves remain intact.每个层次中的"朋友"可能更换了面孔，但层次的数目保持不变。
Few of us, it should be noted, exceed 200 meaningful social relationships. This limit should prompt networking sites to refine their services in a digitally promiscuous age. 应该引起注意的是有些人的有效社交关系超过了200人。该限制应促使社交网络平台采取应对当今信息时代数字化滥交的净化措施。
The enduring human need to connect — a desire that can now be expressed at the touch of a button — should ideally be balanced against the inability of our brains to cope with an excessive degree of digital schmoozing.人类对于亲密关系永恒的需求如今却通过敲打键盘来得以满足，由于过度的在网上闲聊造成我们大脑对维持正常亲密关系功能的下降，这种情况必须扭转。 The enduring human need to connect — a desire that can now be expressed at the touch of a button — should ideally be balanced against the inability of our brains to cope with an excessive degree of digital schmoozing.人类对于亲密关系永恒的需求如今却通过敲打键盘来得以满足，由于过度的在网上闲聊造成我们大脑对维持正常亲密关系功能的下降，这种情况必须扭转。
Instead of the usual binary options to either accept or decline an invitation, there could be a third box to click that is both more gracious and scientifically accurate. 对于一份邀请，除了不是接受就是拒绝这样的二元选择之外，当有第三个更礼貌更科学的选项。
It would read: “It's not that I don't want you to join my network,but I'm just waiting for some space to come up on my fourth layer.” 那就是告诉对方"我并非拒绝你，只因为目前我的朋友圈已满额，假以时日，友友可期"