Yawning has an unexpected influence on the fluid inside your brain
newscientist.com
newscientist.com
That's a simplification, but you get the idea.
Edit: why am I being downvoted for this?
Our ancestors used to have tails. We no longer have tails. Plenty of people wear artificial tails today and get laid, it's not a 100% disqualifying trait
…Do they? What did I miss?
When the woods in eastern Africa changed into savannah, we shifted to two legs and adopted a persistence hunting strategy. The tail became useless, even a liability, and mutations that resulted in reduced tails were not selected against anymore.
No, it isn't. It can be socially impolite to yawn unexcused, when someone is talking to you, as it has come to be interpreted as boredom rather than tiredness or similar. But it isn't inherently impolite to, for instance, yawn when walking down the street, or in a setting where someone isn't talking to you.
What you describe is in my opinion true for western cultures. In Brazil they are not so relaxed about it. Asia even less so.
Because you don’t know what detrimental means in this context and clearly don’t understand evolutionary timescales?
That depends. It can still affect genetic fitness if it affects an individual's ability to confer benefits on their descendants. Of note: most of the most wealthy and influential people in our society are beyond their reproductive years (not technically true for men, but mostly true in practice).
Strangely, dogs sneeze to show deference.
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.
Same goes for sneezing, actually that's even worse for driving, I literally don't see anything for a second at least. Sometimes can be blocked, sometimes not so much.
Is that the paper in question?
I’m looking forward to “yawn to unlock”.
Also, what’s the deal with that article image?
> Anecdotal evidence suggests that yawning helps increase a person's alertness.
> Paratroopers have been noted to yawn during the moments before they exit their aircraft.
Brilliant, I'll use that next time I yawn somewhere inappropriately.
Distinctly remember being outraged.
Makes more sense I suppose if yawning isn't just signalling sleepiness to do it even while asleep!
Or - a change in those fluids makes me yawn?
happens to me a lot when i am on shrooms too