Yawning is something that everybody does. And by "everybody" I mean dogs and people and all other kinds of animals and birds and reptiles. But even though everybody does it, nobody knows exactly why we do it, because it just sort of happens. Which doesn't mean that there aren't a lot of theories about why yawning happens, because there are, and I'm going to tell you a list of some of those theories.
Theory #1: We yawn because our blood needs more oxygen, or at least that's what people used to think. But now scientists have proved that this theory is probably mostly wrong.
Theory #2: We need to stretch our muscles, and we can do this while we are yawning. If our muscles are all stretched, then we are ready to spring into action. And this might be one reason why we yawn if we are nervous, because we think we might have to jump up and run away at any moment.
Theory #3: Yawning is a way of cooling off the brain or even the whole body.
Theory #4: Chemicals in the brain make us yawn. These are the same chemicals that make us feel happy or sad or hungry or whatever. Some chemicals make us yawn more, and others make us yawn less.
Theory #5: People yawn because they feel empathy for other people.
Anyway, these are just some theories, and some of them might be true, and some might be false. I am just telling you what I read about why we yawn. And I have made the theories simple and easy to understand by leaving out lots of details, but if you like details, you can go to Wikipedia and do a search for "yawn," and read them all there.
But now I want to talk about why dogs yawn. Sometimes when dogs yawn, it is because they are bored or tired or sleepy, just like when people yawn. But other times yawning is used as a
calming signal. And the way a calming signal works is like this: maybe you are meeting another dog for the first time, and you want that dog to know that you are not a threat to that dog. So you turn your head and you yawn. This means that you are not challenging the other dog, and there is no need for the other dog to attack you. And if that dog has learned to read doggy body language, he will know exactly what you are saying.
Or another way you can use yawning is if you are in obedience class, and your person is trying to get you to do something, but you don't understand, and you are feeling nervous. Then you can yawn to try to feel calmer and also to tell your person that you are nervous and confused.
People can use calming signals, too. I mean they can use them with dogs. They don't work so well with other people, because if one person yawns at another person, the second person will probably just think the first person is bored, and the second person will be offended. But if a person yawns at a dog who is scared, then the dog will think that person is not so scary.
Oh, and then there is what is called "infectious yawning," which is if one person yawns and then everybody around them starts yawning, too. This can also happen with chimpanzees. And it can happen with dogs, too, because dogs may start yawning if they see their people yawning. Which can mean that the dogs are trying to calm their people because they understand that the people are nervous or excited. Or maybe it just means that everybody got tired and sleepy at the same time!
Sometimes just thinking about yawning will make you start yawning, which is kind of what is happening to me right now. So I'm going to stop writing and go take a nap!
Theory #1: We yawn because our blood needs more oxygen, or at least that's what people used to think. But now scientists have proved that this theory is probably mostly wrong.
