A friend will help you move, goes an old saying, while a good friend will help you move a body. And why not? Moral qualms aside, that good friend would most likely agree the victim was an intolerable jerk who had it coming and, jeez, you shouldn’t have done this but where do you keep the shovel?
有句老话说，朋友愿帮你搬家，而好朋友愿帮你搬尸体。怎么会不愿呢？撇去道德方面的顾虑不说，这位好朋友也很有可能认为这个受害者是个令人难以容忍的混蛋，罪有应得，那么，天呐，你不该这么做的，不过你把铁铲放哪了？
New research suggests the roots of friendship extend even deeper than previously suspected. Scientists have found that the brains of close friends respond in remarkably similar ways as they view a series of short videos: the same ebbs and swells of attention and distraction, the same peaking of reward processing here, boredom alerts there.
新的研究表明，友谊的根基比我们猜想的还要深。科学家们发现，亲密的朋友在观看一系列短片时，他们的大脑会以非常相似的方式做出反应：注意力的集中与分散有着相同的起落，时而出现相同的奖励反应高峰，时而又有相同的厌倦警示。
The neural response patterns evoked by the videos — on subjects as diverse as the dangers of college football, the behavior of water in outer space, and Liam Neeson trying his hand at improv comedy — proved so congruent among friends, compared with patterns seen among people who were not friends, that the researchers could predict the strength of two people’s social bond based on their brain scans alone.
视频的内容多种多样，有大学足球的危险、外太空里水的特性、连姆·尼森(Liam Neeson)尝试即兴喜剧表演。与不是朋友的人相比，视频在朋友之间引发的神经反应模式是如此的一致，以至于研究人员甚至可以单凭两个人的大脑扫描推测出他们社会关系的亲疏。
“I was struck by the exceptional magnitude of similarity among friends,” said Carolyn Parkinson, a cognitive scientist at the University of California, Los Angeles. The results “were more persuasive than I would have thought.” Parkinson and her colleagues, Thalia Wheatley and Adam M. Kleinbaum of Dartmouth College, reported their results in Nature Communications.
“朋友之间这种相似程度让我震惊，”加州大学洛杉矶分校(University of California, Los Angeles)的认知学家卡洛琳·帕金森(Carolyn Parkinson)说。结果“比我设想的更有说服力”。帕金森和来自达特茅斯学院(Dartmouth College)的同事塔利娅·惠特利(Thalia Wheatley)、亚当·M·克莱伯恩(Adam M. Kleinbaum)在《自然通讯》(Nature Communications)上报告了他们的研究结果。
“I think it’s an incredibly ingenious paper,” said Nicholas Christakis, author of “Connected: The Power of Our Social Networks and How They Shape Our World” and a biosociologist at Yale University. “It suggests that friends resemble each other not just superficially, but in the very structures of their brains.”
“我认为这是一篇非常有独创性的论文，”耶鲁大学生物社会学家、《互联——社会网络的力量以及它如何改变了我们的世界》(Connected: The Power of Our Social Networks and How They Shape Our World)一书的作者古乐朋(Nicholas Christakis)说。“这表明，朋友之间的彼此相似不只在表面，还存在于他们的大脑结构中。”
The findings offer tantalizing evidence for the vague sense we have that friendship is more than shared interests or checking off the right boxes on a Facebook profile. It’s about something we call good chemistry.
我们能够隐约感觉到，友谊不只是拥有共同的兴趣或是在Facebook个人资料中勾选过多少相应的选项。他们的调查结果给出了我们期待的证明。这与我们所说的“化学反应”有关。
“Our results suggest that friends might be similar in how they pay attention to and process the world around them,” Parkinson said. “That shared processing could make people click more easily and have the sort of seamless social interaction that can feel so rewarding.”
“我们的研究结果表明，朋友在如何关注和处理周围世界的方面可能是相似的，”帕金森说。“这种共同的处理方式会让人更容易成为朋友，拥有令人感到满足的、彼此契合的社会交往。”
Kevin N. Ochsner, a cognitive neuroscientist at Columbia University who studies social networks, said the new report is “cool,” “provocative” and “raises more questions than it answers.” It could well be picking up traces of “an ineffable shared reality” between friends.
哥伦比亚大学(Columbia University)研究社交网络的认知神经学家凯文·N·奥克斯纳(Kevin N. Ochsner)称，这份新的研究“很酷”、“令人激动”，且“提出的问题多于回答”。这项研究很可能发现了朋友之间“无法言喻的共有现实”的踪迹。
Ochsner offered his own story as evidence of the primacy of chemistry over mere biography. “My wife-to-be and I were both neuroscientists in the field, we were on dating websites, but we were never matched up,” he said.
奥克斯纳说出了自己的故事，以证明化学反应胜于单单一份个人传记。“我和未婚妻都是这个领域的神经科学家，我们都在用约会网站，但从未被匹配在一起，”他说。
“Then we happened to meet as colleagues and in two minutes we knew we had the kind of chemistry that breeds a relationship.”
“然后我们偶然以同事身份相遇，不出两分钟我们就知道，我们有种能培养出一段感情的默契。”
Parkinson — who is 31, wears large horn-rimmed glasses and has the wholesome look of a young Sally Field — described herself as introverted but said, “I’ve been fortunate with my friends.”
31岁的帕金森戴着大大的角质框架眼镜，有种莎莉·菲尔德(Sally Field)年轻时的朝气。她形容自己性格内向，但也说“很幸运能拥有我的朋友”。
The new study is part of a surge of scientific interest in the nature, structure and evolution of friendship. Behind the enthusiasm is a virtual Kilimanjaro of demographic evidence that friendlessness can be poisonous, exacting a physical and emotional toll comparable to that of more familiar risk factors like obesity, high blood pressure, unemployment, lack of exercise, smoking cigarettes.
近来科学对友谊的性质、结构和演变过程的兴趣激增，此次研究就属其一。在这种热情背后，大量人口统计学数据证明缺乏友谊可能是有害的，造成的身体和情感伤害堪比肥胖、高血压、失业、缺乏锻炼、吸烟等人们更为熟知的风险因素。
Scientists want to know what, exactly, makes friendship so healthy and social isolation so harmful, and they’re gathering provocative, if not yet definitive, clues.
科学家们想要知道，到底是什么让友谊如此有益健康，而社会孤立又如此有害，而他们正在收集的虽然并非决定性线索，但也令人兴奋。
Christakis and his co-workers recently demonstrated that people with strong social ties had comparatively low concentrations of fibrinogen, a protein associated with the kind of chronic inflammation thought to be the source of many diseases. Why sociability might help block inflammation remains unclear.
古乐朋和同事不久前证明，社会联系强大的人有着相对较低的纤维蛋白原浓度，这是一种与慢性炎症有关的蛋白质，通常被视为许多疾病来源。为什么社交能力能阻止炎症目前尚不清楚。
Parkinson and her co-workers previously had shown that people are keenly and automatically aware of how all the players in their social sphere fit together, and the scientists wanted to know why some players in a given network are close friends and others mere nodding acquaintances.
帕金森和她的同事此前曾经证明，人们对自己社交领域的所有参与者如何互相配合有着敏锐而自觉的意识，而科学家们想知道，为什么在一个既定的社交网络中，一些人能成为亲密好友，而另一些人只是点头之交。
Inspired by the research of Uri Hasson of Princeton, they decided to explore subjects’ neural reactions to everyday, naturalistic stimuli — which these days means watching videos.
受普林斯顿大学尤里·哈森(Uri Hasson)的研究启发，科学家们决定研究实验对象在日常自然刺激下的神经反应——现在这意味着观看视频。
The researchers started with a defined social network: an entire class of 279 graduate students at an unnamed university widely known among neuroscientists to have been Dartmouth’s school of business.
研究人员从一个既定社交网络下手：一所未透露校名的大学内的某一届研究生，共279人。神经学家普遍知道是达特茅斯的商学院。
The students, who all knew one another and in many cases lived in dorms together, were asked to fill out questionnaires. Which of their fellow students did they socialize with — share meals and go to a movie with, invite into their homes? From that survey the researchers mapped out a social network of varying degrees of connectivity: friends, friends of friends, third-degree friends, friends of Kevin Bacon.
这些学生都相互认识，有些还同住一个宿舍，他们被要求填写了调查问卷。他们与哪些同学交往——一起吃饭、看电影，或是邀请回家？根据调查，研究人员绘制出了连接程度不同的社交网络：朋友、朋友的朋友、三度朋友，凯文·贝肯(Kevin Bacon)的朋友。
The students were then asked to participate in a brain scanning study and 42 agreed. As an fMRI device tracked blood flow in their brains, the students watched a series of video clips of varying lengths, an experience that Parkinson likened to channel surfing with somebody else in control of the remote.
随后，学生被邀请参与脑部扫描研究，其中42人同意参加。在学生观看一系列有长有短的视频片段的同时，一台fMRI设备会追踪他们大脑的血液流动情况。帕金森将这一体验比作与掌握遥控器的另一个人一起搜索电视频道。
Analyzing the scans of the students, Parkinson and her colleagues found strong concordance between blood flow patterns — a measure of neural activity — and the degree of friendship among the various participants, even after controlling for other factors that might explain similarities in neural responses, like ethnicity, religion or family income.
通过对学生扫描的分析，帕金森和同事们发现，血液流动的模式——神经活动的一种衡量方式——与不同参与者之间的友谊程度存在高度一致性，甚至在控制了种族、宗教或家庭收入等其他可以解释神经反应相似性的因素后依然如此。

The researchers identified particularly revealing regions of pattern concordance among friends, notably in the nucleus accumbens, in the lower forebrain, which is key to reward processing, and in the superior parietal lobule, located toward the top and the back of the brain — roughly at the position of a man bun — where the brain decides how to allocate attention to the external environment.
研究人员找出了那些特别能显示朋友间模式一致性的区域，尤其是下前脑负责奖励处理的伏隔核，以及位于大脑顶部和后部的顶上小叶——大概就在男士丸子头的位置——这个区域决定大脑如何分配对外部环境的注意力。
Using the results, the researchers were able to train a computer algorithm to predict, at a rate well above chance, the social distance between two people based on the relative similarity of their neural response patterns.
利用这些结果，研究人员能够通过计算机算法根据两个人的神经反应模式的相对相似度来预测他们的社交关系亲密程度。
Parkinson emphasized that the study was a “first pass, a proof of concept,” and that she and her colleagues still don’t know what the neural response patterns mean: what attitudes, opinions, impulses or mental thumb-twiddling the scans may be detecting.
帕金森强调，这项研究是“第一关，它证明了一个概念”，她和同事们依然不知道神经反应模式的含义：扫描可以探测到哪些态度、意见、冲动或神经活动。
They plan next to try the experiment in reverse: to scan incoming students who don’t yet know one another and see whether those with the most congruent neural patterns end up becoming good friends.
接下来，他们打算进行相反的试验：扫描那些相互还不认识的新生，看看那些神经模式最一致的学生最终是否会成为好朋友。