Iñaki Echeverría-Huarte, an applied physicist at the University of Navarra in Spain, was studying whether people maintain a certain distance between one another while walking when he noticed something strange. Across some 40 experiments, most of his participants spontaneously veered to the left.

在研究人们行走时是否会彼此保持一定距离时，西班牙纳瓦拉大学的应用物理学家伊尼亚基·埃切韦里亚-瓦尔特注意到了一些奇怪的现象。在大约40个实验中，大多数参与者会不自觉地向左偏转。

Although this observation had nothing to do with his original research, it piqued his curiosity. “This was the first signal that something weird was happening,” Dr. Echeverría-Huarte said.

尽管这一观察结果与他最初的研究无关，却激起了他的好奇心。“这是第一个信号，表明有些奇怪的事情正在发生，”埃切韦里亚-瓦尔特博士说。

He and his colleagues assumed there must be a straightforward explanation. Perhaps the layout of the room, for example, was subtly directing people to list to the left. They began what they thought would be a simple investigation to find the answer.

他和同事们起初认为，这背后必定有一个简单明了的解释。例如，许是房间布局在不知不觉中引导人们向左倾斜。他们开始着手调查，并认为这会是一项很容易找到答案的研究。

Five years later, Dr. Echeverría-Huarte and his colleagues have exhausted most of their hypotheses and are no closer to solving the mystery. But what they have found, as reported on Wednesday in the journal Nature Communications, is a striking, innate tendency for people across demographics, cultures and conditions to veer in a counterclockwise direction.

五年过去了，埃切维里亚-瓦尔特博士和同事们已穷尽了大多数假设，却仍未解开这个谜团。不过，正如他们周三在《自然·通讯》期刊上发表的论文所报告的那样，他们发现了一个引人注目的现象：不同人口群体、不同文化背景、不同实验条件下的人都表现出逆时针运动的天然倾向。

“In principle, there is no reason for the fact that people prefer rotating counterclockwise,” said Iker Zuriguel, an applied physicist at the University of Navarra and a co-author of the study. Yet it’s clear they do.

“原则上，没有理由认为人们会偏好逆时针旋转，”该研究的共同作者、纳瓦拉大学应用物理学家伊克尔·苏里格尔说。然而事实摆在眼前，人们确实如此。

Dr. Zuriguel and Dr. Echeverría-Huarte first searched in the scientific literature for an explanation as to why this might be so. They found a study showing that people who are lost usually wander in circles — but it did not specify the direction.

苏里格尔博士和埃切韦里亚-瓦尔特博士首先在科学文献中寻找对此现象可能存在的解释。他们发现了一项研究，显示迷路的人通常会绕圈走——但并未指明方向。

They found another paper showing that when people encounter a wall, those who are right-handed tend to turn left, while those who are left-handed do the opposite. Most of the participants in the original study were right-handed, so “the moment we saw that, we said, ‘OK, we have an answer,’” Dr. Zuriguel said.

他们还找到另一篇论文，表明当人们遇到墙壁时，惯用右手的人倾向于向左转，惯用左手的人则相反。由于原始研究的大多数参与者是右撇子，所以“当我们看到那一点时，我们说，‘好了，有答案了，’”苏里格尔博士说。

To check, they ran their own trial. They separated participants according to whether they turned left or right when directed to approach a wall. They then asked the participants to walk around a small arena. To the researchers’ surprise, regardless of the wall-turning preferences or handedness, most chose left.

为了验证这一点，他们进行了自己的实验。他们根据参与者在接近墙壁时选择向左转还是向右转进行分组，然后要求他们在一个小型场地内行走。令研究人员惊讶的是，无论参与者的转向偏好或惯用手如何，大多数人都选择了向左移动。

This baffling finding prompted them to undertake five additional experiments, each targeting a different hypothesis and involving a total of 573 participants. Yet again and again, they found the same result. In an open schoolyard, for example, the researchers instructed participants to roam at will while a drone recorded their movements. Within seconds, 80 percent of people were moving in a counterclockwise direction. “It’s not a gradual drift but rather a bias that emerges almost immediately,” Dr. Echeverría-Huarte said.

这个令人困惑的发现促使他们进行了另外五项实验，每项实验针对一个不同的假设，总共涉及573名参与者。然而，他们一次又一次地得到了相同的结果。例如，在一个开放的校园操场上，研究人员让参与者随意走动，同时用无人机记录他们的行动轨迹。几秒钟内，80%的人开始沿逆时针方向移动。“这不是逐渐的偏移，而是一种几乎立刻显现出来的倾向，”埃切韦里亚-瓦尔特博士说。

Dr. Echeverría-Huarte and his colleagues wondered if the behavior might be emerging collectively, similar to how pedestrians split into two opposite-moving lanes on crowded sidewalks. But when they tested participants alone, 75 percent still moved counterclockwise, suggesting that the tendency is individual.

埃切维里亚-瓦尔特博士和同事们怀疑，这种行为是否是一种集体效应，就像拥挤人行道上的行人会自动分成两个相反方向流动的队列一样。但当他们让参与者单独进行测试时，仍有75%的人朝逆时针方向移动，表明这一倾向属于个体行为。

Were there cultural factors behind that preference? Pedestrians, for example, typically walk on the same side as cars drive on in their country, and pedestrians also typically move in that direction if they encounter an obstacle. So the team ran experiments in Japan, where pedestrian lanes form on the left. Despite being convinced they would see the opposite pattern to the one in Spain, the researchers yet again observed participants moving counterclockwise, ruling cultural norms off the list.

这种偏好背后会不会存在文化因素呢？例如，行人通常会按照本国车辆行驶方向相同的一侧行走，在遇到障碍物时也往往会朝那个方向移动。因此，研究团队在日本进行了实验，因为日本的人行通道通常靠左通行。尽管研究人员原本确信会看到与西班牙完全相反的模式，但他们再次观察到参与者朝逆时针方向移动，从而将文化习惯排除在可能原因之外。

Finally, they wondered if some unacknowledged social convention drilled into adults, but not yet present in children, might be at play. They reached out to researchers who had conducted a prior study in a Japanese kindergarten in which 52 children moved at random while music played. The Japanese researchers shared their videos of the children for analysis — revealing that most of them also moved counterclockwise.

最后，他们想知道，是否某种在成年人身上根深蒂固、但尚未在儿童身上出现的未被察觉的社会惯例在起作用。他们联系了此前在一所日本幼儿园进行过一项研究的研究人员，在那项研究中，52名儿童伴随着音乐随机走动。日本研究人员分享了他们拍摄的视频以供分析——结果显示，大多数儿童也是逆时针移动。

Enrico Ronchi, who models emergency evacuations at Lund University in Sweden and was not involved in the research, said the findings “open up many new, interesting avenues in the field of crowd dynamics.”

瑞典隆德大学研究紧急疏散模型的学者恩里科·龙基表示（他未参与这项研究），这些发现“为群体动力学领域开辟了许多全新而有趣的研究方向”。

He would be interested to see, for example, whether the counterclockwise bias holds up among people with disabilities, or in emergency evacuations.

他表示，很想知道逆时针偏向在残障人士或紧急疏散情境下是否依然成立。

Karol Bacik, an applied mathematician at M.I.T. who was also not involved in the research, said the new finding challenges our understanding of human locomotion. “The counterclockwise bias may have far-reaching consequences for everyday pedestrian traffic, but we simply have not looked for them yet,” he said.

同样未参与该研究的麻省理工学院应用数学家卡罗尔·巴齐克表示，这一新发现挑战了我们对人类运动方式的理解。“逆时针偏向可能对日常行人交通产生深远影响，只是我们此前从未留意过，”他说。

Dr. Zuriguel and Dr. Echeverría-Huarte next plan to investigate new hypotheses about the counterclockwise bias using biomechanics, virtual reality, neuroscience or even animal behavior. “Fish are the canonical animal that move in circles,” Dr. Zuriguel said. “But whether they prefer rotating in one direction or the other, I don’t know.”

接下来，苏里格尔博士和埃切维里亚-瓦尔特博士计划从生物力学、虚拟现实、神经科学，甚至动物行为学等角度，继续探索关于这种逆时针偏好的新假说。“鱼类是典型的绕圈运动动物。”苏里格尔博士说，“但它们是否偏好某一方向，我还真不知道。”