One of the most significant differences between the short story and the movie is the developing of Charlie's character in the story. In the book for example, is nothing said about his family, whereas in the movie is told a lot about his childhood and in the end he also sees his mother. When we see Charlie in the movie identifying himself as lonely, he becomes a more described character than he is in the book. This shows the difference that in a short story we have to develop a character ourselves, but in a movie only throughout one picture of a person we already get a description of this character we would never have got in a short story. In the movie we have seen the information about Charlie we immediately get it supported by information about his family.
There are also different kinds of pathos in short story and movie. With the identification of Charlie Ms Kinnian and indirectly Algernon with the loneliness in the movie, they identify themselves as sad. This makes the movie much more pathetic than the short story, because in the short story only the identifying between Charlie and Algernon takes place, which is much less pathetic. What also support the pathos in the movie is the whole emotion around the relationship between Charlie and Ms Kinnian. This could represent the fact that a movie has to be more emotional than a short story, so that the people want to see it. But it could also show that someone who is making a movie has to bring in more pathos in his story, because he shows the story omniscient. That means he has not the chance to tell the story in diary-form and so directly out of the brain of