This one trick will tell you if someone is a true friend

It's all in a laugh

How do you know if your friends are truly your friends? According to a new study, it’s all in a laugh.

Researchers from the University of California asked almost 1,000 people from 24 societies across the world to listen to one-second recordings of people laughing together.

The study found that despite such short recordings, participants were able to correctly identify which pairs were friends and which pairs had just met. In fact, 61% could tell the difference.

‘Laughing isn’t necessarily just about communication between the people who are laughing, but potentially it might be a signal to outsiders that gives them some information’ said cognitive psychologist and study co-author, Greg Bryant.

He added: ‘A group of people laughing at a bar might be producing a chorus of signals to others without really being aware of it.’

A quick burst of laughter is a key social signal, Bryant and his colleagues suggest, saying it may help ‘newcomers’ or ‘outsiders’ who hear it to make quick and assertive judgments about the status and relationships within social groups.

So, next time you crack a joke listen hard to how your pals respond. You can probably tell a lot about whether they actually like you from their chuckle.