[extropy-chat] extension of jolly good theory

[Spike]

> Then came the blinding flash of insight, why it is that 
> jolly and portly go together:
> Recall the classic spring mass system, the resonant 
> frequency being square root of the spring constant divided 
> by the mass, or (k/m)^.5 (remember that from physics 101?)...
> Now you understand why. spike

I thought of an extension of the jolly good theory.

If you have had an opportunity to dissect a mammal, you
are likely aware of the fact that all mammals are of
similar enough design that a structure in one has
an analog in the other.  If you find an organ or structure
in a cat, there is an analog of that organ or structure
in you.  The shape and size may be different, but there 
is a nearly one to one correlation.  This observation
made in my youth is supported by the recent findings
that mammalian genomes are all remarkably similar.

Insight: if analogous structures then analogous functions.
humans grin, chimps grin, dogs snarl.  Analogous functions,
different meanings.  A human grin is mirthful and friendly,
but a dog's snarl means "Back off, before I tear you a new 
asshole."

A chimp's grin has a meaning about halfway between these
two according to Sagan's Shadows of Forgotten Ancestors:
a grinning chimp is apparently saying "See my teeth?  I 
could bite you with these.  But I won't, because you are 
my friend.  Don't push your luck, hairless biped."

The jolly good theory explains laughter as a natural
frequency with the diaphragm as the spring and the
mass of the gut as the mass.  My notion is that some
mammals have an analogous function, even if the meaning
is different.  Hyenas make a sound that has been described
as laughing, perhaps as a means of terrifying predators.
Chipmunks and squirrels make a sound that to me resembles
laughter, possibly to warn off competitors.

Nowthen, here is what puzzles me.  I have been in situations 
where I was completely unable to supress laughter, most of 
us have.  This leads me to the following questions:  Do all 
humans and human societies have laughter?  Do all humans 
have *involuntary* laughter?  Is there anything analogous 
to that in other mammals?  If involuntary laughter universal 
in humans, how does that response get hardwired to our sense 
of humor?  Should I stick with rocket science?

spike