Why do we laugh?

         Laughter surrounds everyone.  Baby’s start to laugh at about three point five to four months.  But why do we laugh? Some people say that we laugh because it is a way to communicate.  Everyone understands what laughing is.  Others think that laughter is just a human emotion that we display.  We laugh because it is a way to show our feelings to something.  Everyone laughs.  Why do you laugh?