A hearty¹, belly laugh means the same thing on every continent: joy. But when we laugh with someone else, our chuckles² may divulge³ more than we realize.

每一个大洲，发自肺腑的捧腹大笑都意味着同一件事，即快乐。但也许我们不曾留意，我们和他人一同笑的时候，笑声会出卖我们。

Scientists have found that people around the world can tell whether folks are friends or strangers by listening to them laughing together. And the ability transcends⁴ culture and language.

科学家们发现，世界各地的人都可以辨别出一起笑的人是友人还是陌生人。而这一能力跨越文化与语言。

The study, published in the Proceedings⁵ of the National Academy of Sciences, used a simple experiment. Psychologist Gregory Bryant recorded pairs of college students having conversations. Some were friends. Some hardly knew each other. He then isolated⁶ out just the parts in which the two people were laughing. Each cut was only about one second long.

这一研究做了一项简单的实验，发布在美国的国家科学院学报上。心理学家格里戈尔·布莱恩特记录了对话中的一组大学生，有些是朋友，有些彼此几乎不认识。然后，把笑声部分单独区分出来，每一段截取音频仅历时一秒。

Then Bryant and his colleagues at the University of California, Los Angeles, had volunteers listen to the clips of laughter and guess whether the people were friends or strangers. They ran the experiment in 24 societies around the globe, including indigenous⁷ tribes in New Guinea, tiny villages in Peru and cities in India and China.

布莱恩特和他加州大学洛杉矶分校的同事们让志愿者们听截取的笑声音频，然后猜是朋友还是生人。这项实验在全球24个社会团体里展开，包括新几内亚土著部落、秘鲁的小乡村还有中国和印度的城市。

People weren't perfect at the task. They were good at telling whether women were friends. But for other pairs — like two men laughing — it was harder. On average, listeners guessed correctly only about 60 percent of the time.

任务完成也并非百分百完美。人们擅于判断女性是否是朋友，而其他几组人，比如两名男士在笑就较难判断了。平均而言，听众可以只能猜关系大约只能猜出百分之六十。

Details about what laughter means require cross-cultural studies. Even in the most remote places on Earth, a laugh among friends is a special sound.

具体笑意味着什么需要跨文化研究，即便地球上最遥远的地方，朋友间的笑声也总是特别的。