Scientific explanation for laughing?

[Kerrie]

what triggers laughter? i am speaking of the kind that brings you to tears, makes your belly shake, makes you smile real big...what chemicals are responsible for true laughter? or is it a socially learned response?

[hypnagogue]

I don't know the exact science behind it, but you pose the question as if neurochemistry and learned social behavior are two mutually exclusive things when in fact they are different names for the same thing. If you learn a behavior what you have done is forged a new set of neural connections in the brain, and neurons propogate their signals through the brain via neurotransmitters (chemicals).

That having been said, it's a good bet that dopamine and/or seratonin are involved in the subjective experience of humor. I'll leave it to someone with more knowledge on the matter to give a more definitive answer.

[Loren Booda]

A theory of mine is that one is more ticklish nearer the heart (for most of us, on the left side of the chest near that elbow), a protective reflex causing the arm to clench and submissive "laughter" to ensue.

Laughter is also one of those adaptations, like social hierarchy, that displaces social tension. In this manner, it can be used to ridicule or express approval.

[Ivan Seeking]

Researchers help unravel the mechanics of laughter
What’s going on in our brains when we giggle and guffaw?
http://www.artsci.gmcc.ab.ca/people/easterbrookm/index/mechanics.htm

But why laughter ? Why this explosive, repetitive
sound? To an ethologist, on the other hand, any stereo-
typed vocalization almost always implies that the
organism is trying to communicate something to others
in the social group. Now what might this be in the case of
laughter ? I suggest that the main purpose of laughter
might be for the individual to alert others in the social
group (usually kin) that the detected anomaly is trivial,
nothing to worry about. The laughing person in e¡ect
announces her discovery that there has been a false
alarm, that the rest of you chaps need not waste your
precious energy and resources responding to a spurious
threat (or, perhaps, also to playfully censure minor viola-
tions of social taboos and norms). P 8 of 10

http://redwood.ucdavis.edu/bruno/psc129/handouts/rama3.pdf


Some related links:
It's a touch funny, but studies on tickling are serious
By Usha lee McFarling
Mercury News Washington Bureau
December 1, 1998
http://members.tripod.com/Bagelfather/funstuff/ticklenews2.html

The neurology of laughter also suggests new candidates for neural structures affecting rivalry.
http://psy.otago.ac.nz/r_oshea/br_laughter.html


Study Says Tickling May Aid In Depression:
http://namipa.nami.org/spring99/tickling.html

[Mentat]

Wasn't there also a theory (or, at least, an hypothesis) that laughter was a stifled cry during infanthood (if that's even a word...I mean during the time when you are an infant [t)])?

[Loren Booda]

Infancy. Too many words and not enough time.