"Genre gives the story-tellers a kind of security"

Genre is very important in the direction of the story telling. Genre gives the story teller a safety net that they can fall back on as the audience has an understanding of the subject area already. This is normally evident in costume dramas and historic films as the audience can feel instantly settled in the story world as they already have preconcerted ideas of the what is happening and what it should look like.

This is obvious in films such as saving private Ryan.  When walking through large open fields its eerily silent and looks almost normal however the audience already knows that this wont last for long due to their pre gained knowledge. This pre gained knowledge furthers the story world and once again has the audience subconsciously participating.