Today’s Wonder of the Day was inspired by Awad. Awad Wonders, “Why is looking at people who yawn will make us contagious?” Thanks for WONDERing with us, Awad!

Are you feeling sleepy? Maybe you’re dreaming of a nice, long nap to recharge your batteries. Think about sleep for very long and you may find yourself letting out a wide, drawn-out YAAAAAWWWWWN!

If you’ve been WONDERing with us for a while, you may have read about why people yawn. The answer is . . . no one really knows! While scientists have many ideas, there’s no single explanation for why humans yawn.

Still, there is one thing experts know about yawns—they seem to be contagious! Have you ever caught a yawn from someone else? Most people have. In fact, a person is six times more likely to yawn after seeing someone else do so.

Why is yawning contagious? That’s another mystery experts are still working to solve. They’ve done many studies into why yawns seem to pass from person to person. As a result, experts have a few theories for the reason behind it.

One possible explanation has to do with something called social mirroring. This is triggered by mirror neurons in the brain. These cells help the brain notice useful behaviors in others and then mimic them. When one person sees another yawn, their mirror neurons observe the action and interpret it as beneficial. That may cause them to yawn, too.

Another popular theory is that yawns are contagious thanks to social bonds. In fact, many experts believe they may be a sign of empathy. Humans are undoubtedly social creatures. They form friendships, families, and live together in groups. That’s why many people mirror others, such as smiling when another person does so. Yawning may be just another example of this. In fact, research has shown that people are most likely to catch a case of the yawns from another person if the two share a social bond.

The answer could even be that yawns aren’t truly contagious at all. Instead, people may yawn when they’re together simply because they’re in the same environment. Experts say many things may trigger yawning—including temperature and time of day. Possible triggers may be experienced by anyone in the same general area. For that reason, people yawning after each other may be a coincidence.

Whatever the explanation, experts do know that contagious yawns aren’t limited to humans. One study followed two prides of lions in South Africa. It found that these animals also caught each others’ yawns. In fact, a lion was 139 times more likely to yawn after watching another pride member do so.

Scientists have seen similar behaviors in other mammals. Primates, wolves, and even domestic dogs seem to experience contagious yawns. In some cases, this may even cross between species. For example, pet dogs are more likely to yawn after seeing their owner do so.

Think about the last time you yawned. Was it after watching another person do the same? Or did you start the yawning and pass it to others? Either way, yawning often becomes a group activity!

Standards: NGSS.LS1.D, NGSS.LS2.D, CCRA.R.4, CCRA.R.10, CCRA.L.3, CCRA.L.6, CCRA.R.1, CCRA.SL.1, CCRA.L.1, CCRA.W.3, CCRA.SL.3, CCRA.L.2, NCAS.A.1, NCAS.A.2, NCAS.A.3

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Learn to stand up against bullying in tomorrow’s Wonder of the Day!