Ginny - So, we all know what yawning is, but there are actually two forms. There's the form that you do when you're tired or you're bored, and then there's the other form which is contagious yawning, which is what happens when you see someone else yawn or even just hear people talking about yawning. I predict that by the end of this news story, at least one person in the studio will have yawned. This is really interesting because actually, humans aren't the only ones who do it. Chimps do it as well and even dogs can catch their owner's yawn. But no one really knows why it happens. It had been thought that it related to empathy. So, you're trying to empathise with someone, understand what they're feeling, so you're sort of mirroring them. But this new study from a group from Duke University in North Carolina actually studied over 300 people. So, it was quite a big sample size. They found that actually, empathy didn't relate to how likely you were to yawn after watching a 3-minute video of people yawning. They tested people twice. They got them to watch this video and some of them, they tested in the lab and then some of them at home, and then some of them it was at the lab twice and lots of different combinations. What they did find which is really interesting is that it was a very stable trait, how likely you were to yawn. So, if you yawned the first time you watched it, you're likely to yawn the second time. They were trying to work out what other sort of personality traits or factors might affect your likelihood of yawning.
Chris - So, were there some people are really yawn-resistant then?
Ginny - Yes, there was...
Chris - So, we need them as listeners, don't we?
Ginny - Well no, because I'm assuming you're not talking about contagious yawning. You're worried about people yawning through being bored.
Chris - And it doesn't apply.
Ginny - No, this is just contagious yawning. But yeah, they found some people just don't yawn at all. Some people are really resistant to it. And actually, they asked those people whether they were just suppressing it and they said, no. They said they didn't feel like doing it. I'm a contagious yawner. Even when just reading this paper, I was yawning a lot. I'm kind of suppressing one now in fact. So, they were looking for different factors that might explain why some people yawn and why others don't. And they found that age was important. So, older people are actually less likely to have contagious yawns. But that only explained 8% of the variation.
Chris - It wasn't because they were asleep already.
Ginny - No, it wasn't that.
Chris - Just checking.
Ginny - But yeah, 8% which is a tiny amount of this variation. Once that had been taken into account, empathy and other things like the time of day they were watching the video, the people's intelligence, none of that seemed to have an effect. So, the group are now wondering whether there's a genetic link because if it is such a stable trait that some people are yawners and some people aren't, it may be that that's something to do with genetics. And these all might sound quite frivolous, but actually, we know that people who have conditions like Schizophrenia and Autism don't experience contagious yawning as much. So, if we can understand a bit about why some people do and why some people don't, that might shed some light on those kind of conditions.