笑声与哭声是全世界通用的语言，也是人类社交沟通的支柱，人生中无数难忘时刻－婴儿出生、牙牙学语、甜蜜初恋、摰爱消逝－皆以笑声哭声作背景音乐。然而，有关笑与哭这两种人类行为的科学研究，却少得可怜。我们为何会发展出这些不寻常的声音沟通技巧？这种表达情绪的声音，是人类独有的吗？从婴儿这种只懂哭与笑的生物身上，又可以有什么发现呢？有赖一群认知脑神经科学家、心理学家以及进化生物学家的努力，我们得以对笑与哭的世界深入探讨，并发现原来这两种行为有很多共通之处。

Laughing and Crying
The unmistakable sounds of laughing and crying are recognizable the world over. They are pillars of human communication and social interaction. Both are the soundtrack to our lives’ most memorable moments - births, first words, first loves and final losses. And yet, researchers will tell you when it comes to studying human behaviour there is nothing as poorly understood as laughs and tears.

Why did we develop these unusual vocal communication techniques? How uniquely human are these emotional sounds? What can we learn by studying creatures who can only cry or laugh, you know, babies? Thankfully, cognitive neuroscientists, psychologists and evolutionary biologists are exploring the worlds of laughing and crying. Surprisingly, they’re learning that these behaviours have a lot in common.