alt Hacker NewsThe contagious nature of yawning is so weird. It has to be evolutionarily advantageous because it's so wide spread, but it's also non-obvious.
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Yawing seems like it must be adventurous, the contagious part not so much.
Even the mention of a yawn can trigger it.
Perhaps we are almost always in a state of needing a yawn, but the trigger is seldom met, and seeing or hearing about it is enough to make our brain go "oh yeah I forgot about that".
Perhaps yawning is actually underdeveloped and an ideal human would yawn at regular intervals without any prompting.
A trait doesn’t have to be advantageous to persist just non-detrimental.
There's probably a strong survival advantage in convincing whoever is leading a meeting that it's time to adjourn.
It's a bit like laughing. Synchronise the mood of the group. I assume other mammals have contagious yawns too?
I assumed it was a kind of warning system: "Another member of the tribe detected impairment/fatigue and took measures to become more alert, perhaps you should raise alertness also."
It is strange how well yawning is conserved, even as far back as in reptiles, since it doesn't really seem to do anything.
Just about all our behaviors are contagious. Scratching, deep breath, emotion, looking in a certain direction, sudden alertness. If yawning were different, that would be weird.
contagi-yawn
I literally yawned as I clicked on this article from my RSS reader. The contagious nature at the mere idea of a yawn is wild.