I have been researching August Sander and have come to the conclusion that he is one of the most key figures in the development of portrait photography. His method was based around the idea that he could depict the character and identity of a person via the facial expression, clothing and props and the background in which they are set.
Douglas Huebler took a rather tongue in cheek look at this with his variable piece 101, in which he got Bernd Beecher to pose as different characters, he got him to look at the results some months later and published them as Bernd Beecher remembered them rather than as they were first shot.
From my research and reading I suspect that the truth is that it is the photographer that creates an identity for the sitter, which may be carefully constructed to reflect the reality of the person or constructed in such a way as to reflect a desired image like a picture of an actor displaying them as the character rather than themselves. I suspect this theme will be a big part of the rest of this course.