Contagious yawning

How it works

Everyone yawns. Yawning is seen in fish, birds, and mammals, and human babies yawn before birth¹. Catching a yawn from someone else is different. It is a social reflex, and only some animals have it.

The trigger can be seeing a yawn, hearing one, reading the word, or simply thinking about yawning¹. The response is not immediate. It usually arrives within a few minutes.

The effect is linked to the social brain. Some studies find that people who score higher on empathy tests catch yawns more often. Other studies find no link, and the question is still open¹². In lab tests, contagious yawning becomes much more common at about age four⁴. Contagious yawning is weaker in autistic people¹ and in people with high psychopathy scores⁵. It is stronger between friends and family than between strangers¹.

Dogs catch yawns from humans, and chimpanzees catch them from each other¹. Why yawning is contagious at all is still debated. One idea is that it helps a group stay alert at the same times. Another is that it is a side effect of copying what other people do¹.

How common it is

Lab studies find that about 30% to 70% of people yawn when they see yawning videos. Some recent studies find only 15% to 20%³. The rate is lower in young children, lower in autistic people, and higher between people who know each other well¹. No large, representative population survey has measured it, so any one percentage is a rough guide.

Try it

1. Read this sentence about a big, slow, jaw-stretching yawn.
2. Watch a one-minute video of people yawning.
3. Set a timer for five minutes and count how many times you yawn.
4. Try the same on a friend without telling them what you are testing.

In lab tests, about 30% to 70% of people yawn at least once²³. Not yawning is common too.

Is it a problem?

No. Catching a yawn is not a sign of tiredness in the catcher, and not catching one is not by itself a sign of poor empathy². It is a normal social reflex that varies naturally between people. There is nothing to check with a doctor about contagious yawning itself. Frequent, uncontrollable yawning unrelated to sleep or to seeing others yawn is a different matter and is worth mentioning if it is new.