The narrators perspective on the story has an immense effect on the story is told. Nick, our narrator, gives you an extremely unbiased look on the story. how he was brought up, was to not voice his opinion and when he feels as though he should, to remember that not everyone had the advantages you had. Nick's family is described briefly as at least middle class. So, as a result of his upbringing, I believe, He doesn't voice his opinion; therefore giving a perfectly un-bias prospective.
When observing a situation, you can almost guarantee that you are getting a true look. He doesn't put his own beliefs or thoughts to skew what is actually happening. he is a passive person, so he is not aggressive enough to engage but it is his nature to observe. so not only do you get the story from an un-bias source, but a full story.
shawn guthoerl