http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0063441
Primary types of laughter..tickling,
Joyful,
Social,
Taunting,
with lots of other smaller nodes, Schadenfreude, sexual and other variances of social.
Remember kids, laugh and the world laughs with you. Study humor and the world becomes a barren planet...except for new funny.