Double-yawn effect

You can check out some of the thinking on why it's contagious here. Interesting that they mention human to dog yawning contagiousness. I've yawned a time or two after seeing my dog yawn right after a nap. Maybe they should check out for reverse dog to human contagiousness also.

http://en.wikipedia.org/wiki/Yawn#Contagiousness

 

The wiki article is kind of a collage.

I thought this paragraph was pretty peculiar:

For me yawning seems like crossing a threshold from forced, sustained activity or vigilance to relaxation. The deep breath and the whole "pandiculation" thing result in a more sloppily relaxed, less sharp state. This sentence: "It signals tiredness to other members of the group in order to synchronize sleeping patterns and periods." made much more sense to me than the earlier proposition that it increased group vigilance. In my experience yawning is more likely to precede sleep than anything else. Who really feels more alert and vigilant after yawning?

The best mechanism I've heard of for how a yawn might be "contagious" is the proposed mirror neuron one. Mirror neurons could account for a huge mass of things, but as far as I know it's a notion that hasn't been more than just sketched out.

 

I had a similar reaction to the wiki article zooby. Here's another article that discounts some of the things in the wiki article. According to this one, there's no basis for thinking it removes excess CO2 from the body, something I was told a long time ago. Anyway, I did yawn once while reading this one. Anyone else?


http://faculty.washington.edu/chudler/yawning.html

 

If yawning is a means to keep the brain cool, why don't we see joggers yawning all the time?

 

Just by reading the title but I was already feeling sleepy - it was just the tipping point.