1 min
Why are yawns contagious?
When you see someone yawn, your brain quietly rehearses the same movement. And the more easily you catch a yawn, the better you tend to be at feeling what others feel.
Answer
You are sitting in class. Someone across the room yawns enormously — and before you have decided anything, your own mouth has already opened. What happened?
The leading explanation points to mirror neurons. When you watch someone yawn, these neurons quietly run a copy of the movement inside your own brain, like a replay playing in your head. Your body then copies the homework.
What is more interesting is that how contagious a yawn is depends on empathy — how well you read other people's feelings. Studies find that people who are good at sensing how others feel catch yawns easily, while people who find it harder are almost immune. Your dog catches your yawns too, which makes it a cross-species effect.
Scientists think yawning may be a group synchronising signal: getting sleepy together and waking up together keeps a group moving on the same rhythm and staying alert as a group. So the next time you catch a yawn, do not blame your willpower. It probably means you are good at feeling what other people feel.
In one line: catching a yawn is not a failure of self-control — it is your brain quietly feeling something on someone else's behalf.
Michael's Thought
So catching a yawn is not weak self-control — it means I am good at feeling what others feel. I like that.
Sources
Related WHYS
Why does a mint candy feel icy cold when it is just room temperature?
A mint candy cools nothing down, yet it feels like ice. Menthol simply flips the body's cold switch, TRPM8, so the brain receives a fake message that says cold.
Why do we hiccup, and why can't we stop?
A hiccup is not a random twitch: the diaphragm jerks, then the glottis snaps shut about 35 milliseconds later, cutting off the air. Hiccups have been recorded only in mammals — and tadpoles use almost the same reflex to push water over their gills.
Why do your fingers wrinkle in water?
Wrinkly fingers are not swollen skin. Your nerves tell the blood vessels underneath to squeeze shut, the fluid is pulled away, and the skin sinks into folds. Nerve-injury patients gave the secret away back in 1935.