Why do people laugh?

Laughter is a common behavior in human society. We laugh and we often hear others laugh—in various forms, such as silent giggles, small chuckles, and loud laughter. Laughter is so common that ordinary people may have the illusion that "laughter is a simple thing." But in fact, laughter as a research topic has puzzled scientists for centuries. To this day, it is still worth studying in depth "why we laugh."

If you ask this question to ordinary people, the easiest answer to get is definitely: because they heard humor and jokes.

This is only part of the reason. The actual reason is much more complicated than "humor". Psychology professor Robert Provine has systematically studied the behavior of laughter since the 1990s. At that time, the theory to explain laughter had not yet been fully formed, and Provine started his research from scratch. The first difficulty he encountered was that it was difficult to produce spontaneous and real laughter in the laboratory, and the samples of laughter had to be collected from human society. After long-term efforts, Professor Provine gradually established a relatively systematic theory to explain laughter.

For example, Provine believes that human laughter appeared millions of years earlier than language. Before language appeared, laughter was the original form of communication. In addition, most laughter is not a response to jokes or humor. It is mainly the person who causes laughter, not the joke itself. When people laugh, they often have interesting communication intentions. Laughter has the social function of building relationships between different individuals in a group. Of course, laughter is not only positive, but also negative.

Provine's research highlights the powerful connection between laughter and social interaction, and points out a valuable direction for subsequent research.

In 2018, Nature Communications published a study called Similar neural responses predict friendship. Volunteers in the study watched a large number of videos, including comedy videos. During the process, the researchers performed functional magnetic resonance imaging scans on the volunteers to measure their brain activity.

The results showed that people who are friends in real life tend to have similar reactions to the same video. Conversely, if two new acquaintances have similar brain activities, they are more likely to become friends. In layman's terms, it can be said that it is easier to make friends if you have the same sense of humour.

A study by Jared Martin of the University of Wisconsin-Madison showed that smiling does not necessarily constitute positive feedback and can sometimes make people nervous. Of course, the authors also cautioned that the study only included male subjects and the sample size was small. Further research is needed to explore gender differences.

Laughter is simple. But the principle behind it is not. In order to understand the secret of laughter, researchers will continue to conduct in-depth research. It is hoped that a deeper understanding of laughter can help humans live happier and healthier lives.

This article is a work supported by Science Popularization China Starry Sky Project

Team: The Nutcracker

Review: Tao Ning

Produced by: China Association for Science and Technology Department of Science Popularization

Producer: China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.