• Question: why do we yawn, is there any more to it than a bodily reaction to fatigue?

    Asked by juniorscientist101 to Pete, David, Jonathan, Sam on 26 Apr 2012. This question was also asked by sara2012.
    • Photo: Pete Etchells

      Pete Etchells answered on 26 Apr 2012:

      Hi juniorscientist101! Thanks for the question, that’s a really good one. There are lots of reasons why people think we yawn, but no one’s actually sure on the real, original reason. You’re right in that one reason people think we do it is because we’re tired, and need to stretch our muscles – yawning often happens together with a desire to stretch. Some researchers also think that yawning helps to regulate the temperature of our brain, and have done experiments to show that if you cool down someone’s forehead, and show them videos of people yawning, they are less likely to ‘catch’ the yawns themselves. Other scientists think that increases in chemicals to do with emotions – such as serotonin and dopamine – cause us to yawn more.

      So lots of theories, but definite answers yet! What do you think?

Comments

  • Photo: mrgenius

    mrgenius commented on :

    yawns do definitely get passed on. Also if you fake yawn long enough you will actually yawn. Can you explain this please Pete.

    • Photo: Pete

      Pete commented on :

      I think it might be something to do with ‘mirror neurons’ – these are a certain type of neuron in our brain that are involved in mimicking the actions of others. Mimicking is a good thing, because it helps you to learn actions quickly when you’re young, and also helps to form social bonds with your friends and family. It’s especially useful in the development of language, and some scientists think that yawning being contagious is a by-product of this.