I'll start with yawns ...
And, no, I'm not criticizing this thread. It's just that the yawn itself is important here: a yawn results from a need to increase the volume of oxygen intake. Whether the air's impure, or if it's just your brain being tired and demanding more fuel for its work ... the yawn draws greater volume of oxygen into the body and has the short-term effect of livening the brain's activities due to an increase in available oxygen.
So what, then, is laugh? You can laugh yourself sick, or even laugh yourself to a sideache. So think about this: sideaches come from an overabundance of oxygen; as you run short of breath in a soccer (football; I know, but I'm a damn American, so nobody in this country would care, but either way I suppose it works) game, you might tend to breathe raggedly, gulping air. This is when the sideache sets in, no matter how short of breath you think you are. I stand on the merit of these assertions regarding sideaches on the grounds that I have grown up around too many American football coaches, basketball coaches, and running coaches to ever forget that litany. I will also note consistent results under impromptu and varying field tests.
So is a laugh something which draws more oxygen to the body? Sure.
That assertion is a little more ... uh ... yeah. That one's mine, as far as I know, for the moment; I'm making this up on inspiration.
Why draw more oxygen through laughter? Is it possible that among the chemical responses in the brain that make us amused--perhaps when we perceive with our eyes certain cognitively absurd events, or hear with our ears similarly absurd ideas or sounds--that cause the body to prepare for some form of exertion, or that in any way
require greater oxygen consumption? Perhaps something absurd enough to make one laugh will excite a specific response in the brain that causes a set of absurd signals to pass through the body, giving diverse orders throughout the body in a spontaneous electrochemical burst that is followed by no actual process? The result of which is the sensation of extreme happiness and a seizure-like respiratory arrhythmia?
It could also explain why false laughter sounds so damn false: it's an addictive response or perhaps a compulsive response. Why does anyone laugh falsely? Largely because of insecurity in the moment, whereby the brain, seeking to avert an increase in negative feeling,
craves the drug of laughter so that a person is compelled to push out laughter in search of a fix.
In this sense, and even with an addictive edge, the nature of what laughter is makes it one of the most pure, least contrived human acts. It is the nature of good feeling unleashed.
But I'm going to stop now, else I stop making any sense whatsoever.
thanx,
Tiassa