Laughter is a universal signal understandable to people of different countries, cultures and social strata. It changes depending on who we are currently communicating with. Therefore, we can almost unmistakably, only by the sound of the voice, determine the relationship between laughing people, even if we see them for the first time.
It turns out that a friend is known not only in trouble, but also when we joke with him. And most of us can accurately tell if two people know each other well just by listening to them laugh.
To see if laughter is different between friends and strangers and how these differences are understood by people of other countries and cultures, an international group of psychologists conducted a large-scale study1. The students were invited to discuss various topics, and all their conversations were recorded. Some young people were bosom friends, while others saw each other for the first time. The researchers then cut out fragments of audio recordings when the interlocutors laughed at the same time.
With friends, we laugh more naturally and spontaneously, without controlling or suppressing our voice.
These fragments were listened to by 966 residents of 24 different countries on five different continents. They had to determine whether the laughing people knew each other and how close.
Despite cultural differences, on average, all respondents correctly determined whether laughing people knew each other (61% of cases). At the same time, female girlfriends were much easier to identify (they were guessed in 80% of cases).
“When we communicate with friends, our laughter sounds in a special way, — says one of the authors of the study, a cognitive psychologist from the University of California (USA) Grek Brant (Greg Bryant). — Each individual «chuckle» lasts less, the timbre and volume of the voice also differ from the usual — they increase. These features are universal — after all, the accuracy of guessing in different countries did not differ much. It turns out that with friends we laugh more naturally and spontaneously, without controlling or suppressing our voice.
The ability to determine the status of a relationship by cues such as laughter has evolved over the course of our evolution. The ability, by indirect signs, to quickly determine the relationship between people we do not know can be useful in a variety of social situations.
1 G. Bryant et al. «Detecting affiliation in colaughter across 24 societies», Proceedings of the National Academy of Sciences, 2016, vol. 113, № 17.