Can fictional literature be used as data?

I had a professor in my program (graduate, generally qualitative social science) say that literature could be used as data for historical or cross-cultural study. He never went into detail about how exactly this could be accomplished beyond saying that it could shed light on the conventions of the times (word choice, grammatical structure, etc. as well as the more humdrum observations and descriptions of everyday life). Obviously, since we're dealing with fiction, the data is not pure and the interpretation has a lot of pitfalls. It seemed like an interesting thought.

What do you think about this though? What kinds of things could this type of data describe? Has anyone written on this?