If you’re yawning around your friends it’s not because they’re boring it means you have a tight bond. You’ve probably noticed that when someone yawns it’s almost impossible not to yawn too. It’s called “yawn contagion” and it’s a big part of how we humans interact.

Basically, we mimic each other’s actions as a way relating and forming an emotional connection. That’s why people with the inability to connect emotionally, like autistic or sociopathic people, won’t catch a contagious yawn. But a recent study found that the closer you are to a person, the more likely you are to catch their yawn. Scientists aren’t quite sure about the biological need for yawn contagion, but it sure is a handy way to test how close you are to another person!