Secondary Research

The way characters talk in a movie apparently affects the movie more than you may think, and not in the obvious way (cursing). For example, some people claim that the Dreamworks film Shark Tale discriminates against Italian-Americans because of some sharks in the film who are portrayed as gangsters. These fish all have Italian-sounding accents and names such as "Frankie", "Gino", "Giuseppe", and "Lino", the "Codfather"(har har). They also use Italian-like slang such as "Capeesh?". A poll revealed that 44% of teenagers surveyed expected Italian-Americans in movies to have crime-related roles (or work in restaurants). One of the people concerned about Shark Tale's effect is Lawrence Auriana, president of the Columbia Citizens Foundation, an organization dedicated to "preserving the rich Italian-American heritage". What pushes Shark Tale across the line for him is the fact that it's being marketed towards children.
People's perception of movies seems to be mostly based on language. If a movie has lots of witty banter (Serenity), people will generally expect it to be a more intelligent film than a movie with somewhat less sophisticated dialog (Bill and Ted's Excellent Adventure).


NOTE: Neither of those last two films were featured in American Tongues, but those are the best examples I can come up with for movies with different styles of speaking.