What indicates someones laugh in astrology?  Mercury? 

My daughter, 4yrs old, has the most infectious, guttal, jolly laugh you've ever heard!  Ever since she was a little baby.  Her Mercury is in Virgo (3rd or 4th house depending on house system)...but her moon is in Sagittarius which I thought might have something to do with it.  I wish you guys could hear it!

Yeah I would expect Jupiter/Sag would be involved.  My Sag 17 year old has always been funny and jovial. 

Your daughter sounds like an absolute joy.

Comedy and humor is associated with Sagittarius. And since Sagittarius is ruled by Jupiter, than I would say Jupiter is humor. But Mercury gives humor its voice!

So I guess Mercury conjunct Jupiter?

She has Jupiter conjunct her sun and Mars, each one degree apart.  She cracks me up on an hourly basis!  She also has that Venus in Leo, and she is quite an actress.

I don't know what would show it, my astrology isn't that good yet, but I've always been told that I have an infectious laugh.  I laugh big, loud, unconcerned with anyone or surroundings; I chuckle, giggle, and snort constantly.  One of my HS friends' father nicknamed me "Giggles" because of it.

I have Jupiter rising in Cancer, but an afflicted Leo Merc -- conjunct Sun in Leo-Saturn in Virgo.

The funniest people I know have saggy mars

Tomaui,

My Mars is in Sag and I am often told I should do stand-up. :-) Many Sag's I know, esp the women seem to laugh a lot / have good senses of humor. One of my best friends has a great laugh!

I just did a search of some of my favorite comedians. The first, Bette Midler is a Sag. I was thinking most would be fire signs, but strangely enough, most are Taurus!