some laugh cause they are nervous or insecure, or want people to like them.
some laugh cause they are stupid and can't figure out what anyone else is talking about.
some laugh cause they are manic and when not laughing they are in a panic .
i prefer a person who laughs a little bit
and no horse laughers need curl up on the couch with me please .... seems to me those people wet their pants a great deal .... sic