朋友圈真能無限大？

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. 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.

它們每周都會(huì)出現(xiàn)在我的電子郵箱里，一點(diǎn)一點(diǎn)地啃噬著我的靈魂。友善的語言，微笑的表情，以及迎合自尊心的社交邀請，所有這些都被我心懷愧疚地忽視了。原因在于，我認(rèn)同鄧巴數(shù)字(Dunbar’s number)的概念——即我們靈長類動(dòng)物的大腦限制著我們有能力保持的有意義的社交對象人數(shù)，使其不超過約150人——而我在領(lǐng)英(LinkedIn)上的好友人數(shù)已經(jīng)超過了200人。

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; five closest contacts in the innermost layer, then 10 in the next, followed by 35 and 100.

牛津大學(xué)(Oxford university)人類學(xué)家羅賓·鄧巴(Robin Dunbar)教授提出了這個(gè)以他名字命名的數(shù)字。鄧巴發(fā)現(xiàn)，從新石器時(shí)代的村落、羅馬帝國的軍團(tuán)，到一份普通的圣誕節(jié)賀卡寄送名單，人類群體的規(guī)模具有驚人的相似性。他就此提出假說，即我們的社交注意力并不是在150個(gè)知心朋友之間平均分配的，而是像洋蔥那樣分層分布;5個(gè)最親密的聯(lián)系人位于我們社交圈的最里層，外一層是10個(gè)人，再向外的兩層分別是35人和100人。

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. 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. 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.

現(xiàn)在，一項(xiàng)針對手機(jī)通話的研究試圖檢驗(yàn)鄧巴教授的假說——即我們的感情親密度是像俄羅斯套娃那樣分層分布的——進(jìn)而幫助理解我們?nèi)绾谓o自己的社交關(guān)系分層。在芬蘭阿爾托大學(xué)理工學(xué)院(Aalto University School of Science)同事們的合作下，鄧巴教授研究了2007年歐洲的手機(jī)通話數(shù)據(jù)集，這其中包含了3500萬用戶進(jìn)行的總計(jì)60億次通話。兩個(gè)人之間通話的頻率是反映他們感情親密度的近似指標(biāo)。數(shù)據(jù)中剔除了那些僅做緊急呼叫或僅撥打商務(wù)電話的人;只有那些和至少100個(gè)人多次往返呼叫的人被包括了進(jìn)來。

By scanning networks of calls and ap­plying clustering algorithms, researchers found people tended to have either four or five layers in their social onion. 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.

通過梳理通話的人際網(wǎng)絡(luò)和應(yīng)用聚類算法，研究人員發(fā)現(xiàn)，人們傾向于將他們的社交圈劃分為四至五層。平均而言，社交圈分為四層的個(gè)體擁有4個(gè)最親近的知己，往往是親戚，他們與這些人的通話最為頻繁，再向外一層有11人，最外面的兩層分別是30人和129人。

For those with five layers, the number of friends was split slightly differently: three closest contacts; then 7, 18, 43 and 134. 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).

對于那些社交圈分為五層的個(gè)體來說，每一層分布的朋友人數(shù)略有不同：3個(gè)最親密的聯(lián)系人在最里層，往外的各層依次是7人、18人、43人、和134人。上述分析結(jié)果上月出現(xiàn)在了arXiv網(wǎng)站上，科學(xué)家們向這個(gè)網(wǎng)站上傳自己的研究成果用于學(xué)術(shù)討論(有些時(shí)候——當(dāng)然并不總是如此——這是在由同行評議的正式期刊發(fā)表的前奏)。

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. One idea to emerge from the study is that individuals with four layers might be introverts while those with five are extroverts.

盡管根據(jù)這項(xiàng)分析，社交“分層”的概念似乎是站得住腳的，但分析中指出的差異或許意味著，分層的層數(shù)對應(yīng)于不同的社交傾向。從上述研究衍生出的一個(gè)觀點(diǎn)是，社交圈分為四層的個(gè)體也許是內(nèi)向型人，而社交圈分為五層的個(gè)體可能是外向型人。

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. Frequency of contact does not always correlate with depth of relationship; longstanding bonds often do not need intensive tending to bloom.

這篇論文有其局限性：它僅僅考察了一年時(shí)間內(nèi)的數(shù)據(jù)。友誼可以是短暫的，因時(shí)因地而變，并反映我們在特定階段的生活狀態(tài)。聯(lián)絡(luò)的頻率并不總是與友情的深淺成正比;長期關(guān)系常常不需要密集的看護(hù)也能茁壯發(fā)展。

But it is also possible that this 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. 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 a change of circumstances, old acquaintances are superseded by new ones. The exact components of the layers may change but the layers themselves remain intact.

但同樣可能的是，這項(xiàng)研究捕捉到了友誼的獨(dú)特快照：2007年的數(shù)據(jù)集代表了智能手機(jī)普及之前的社交格局，早于人們開始習(xí)慣性地在移動(dòng)設(shè)備上通過Facebook或其他網(wǎng)站維持友誼。研究人員指出，這些數(shù)據(jù)還表現(xiàn)出了頗有說服力的一致性。它直觀地映照出了真實(shí)生活：即便搬家或者換工作會(huì)導(dǎo)致我們所處的環(huán)境隨之改變，老相識(shí)也會(huì)被新朋友所取代。社交分層的具體人員構(gòu)成或許會(huì)發(fā)生變化，但分層本身保持不變。

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. 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.

值得指出的是，我們當(dāng)中幾乎沒有人能擁有超過200個(gè)的有意義社交關(guān)系。這一上限應(yīng)促使社交網(wǎng)站在一個(gè)數(shù)字意義上人際關(guān)系混雜的時(shí)代完善他們的服務(wù)。持久存在的與他人聯(lián)系的人性需要——如今這種愿望按一下按鈕就能得到表達(dá)——最好與大腦無力應(yīng)對過度數(shù)字化交往的局限取得平衡。

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. 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.”

在通常的接受或拒絕一項(xiàng)邀請的二元選擇之外，還應(yīng)有第三個(gè)更有禮貌、同時(shí)在科學(xué)上也更準(zhǔn)確的選項(xiàng)以供勾選。該選項(xiàng)應(yīng)表述如下：“并非我不愿你加入我的社交圈，但我目前還在等待我的第四個(gè)社交層出現(xiàn)空缺。”