Comedy in Cinema is More Realistic Than Drama

In a word?  Defecation. 

Defecation is a large part of daily life, even if most of us would prefer to imagine it isn't.  In fact there are those of us who would prefer to pretend it doesn't even occur.  These people make the majorities of the dramas we see today. 

In Ulysses James Joyce portrayed a man who urinated and defecated as any normal person would, in what was possibly the first truly realistic novel.  The lesson, however, was not learned by the rest of the entertainment industry.  It would still be at least thirty years until even a fart was heard on a movie screen, let alone any actual movements of bowels. 

Today, defecation is still very taboo in films, unless it is a comedy.  So, in this way, comedy is more realistic than the average drama.  However, it should be noted that the only type of defecation allowable even in comedies is of the 'explosive diarrhea' type.