The Surprising Way That People in 24 Countries Can Spot True Friends

If you've ever been at a party with people laughing and thought, "well that was a fake laugh, they probably just met," you were probably right. It turns out that laughter can clue us in on the quality of a friendship between two people.

A new study from UCLA found that people from 24 societies could pick out friends from strangers with 61 percent accuracy just by listening to them laugh. And American listeners had an edge with the ladies: participants from the U.S. could identify female friends accurately 95 percent of the time.

Two women laughing together.

The study tested 966 participants from all over the world who listened to clips of people laughing and had to decide if they were friends or strangers. The researchers tested different combinations of laughers: some were all female, some were all male, and some were mixed male and female.

The chart below shows the accuracy rates of participants in different countries. The three columns on the left refer to laughing between strangers and the columns on the right between friends. In each of the 24 societies, listeners were able to identify female friend "dyads" more easily.

UCLA study rates of accuracy by country and gender.

Primary researcher Gregory Bryant from the University of California Los Angeles told ATTN: that women may have a more genuine quality in their laughter when they laugh with a friend. "Women take a little longer to actually develop a relationship where they are genuinely co-laughing," he said. "Maybe it's a slightly better cue when women do it then when men do it. I didn't predict that when I set out to do this study."

Bryant said that it surprised him that people from such incredibly diverse cultures could pick out friends through laughter. "I think just that the fact that we got such consistent results in such diverse places is really interesting, he said. "Hunter gatherers in Africa are really similar to students in Singapore for example."

Friends laughing.

In what seems like a paradox, Bryant hopes people will take laughter more seriously. "Something as common as everyday laughter should be thought about more seriously as a research subject," he said. "It seems to be a fairly powerful cue of how people know each other."

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