You’re totally right about interiority. I should have gone into that more in the post. Online persona are restricted to the same problem that largely affects movies. In online communication, we are see only what is written, and in movies, we see only the action and behavior of the actors (there is the voiceover, but it takes up linear time from the narrative unlike the interior dialog in a book, which may represent an instant of time). Books allow us to get into the heads of the characters and really see what’s going on (as much or as little as the narrator allows, but at least we can pull back the character curtain somewhat), but online communication is limited to what we observe and how we interpret the data that we receive (which may be widely divergent with a messenger’s intent as evidenced by flamewars).

Also, about the construction of personae: do you think this has to do with the fact that literary narrative gives us access to interiority? Online, as you say, we only interact with what people say, but in literature (at least, a lot of literature), we are told by the narrator what people are actually thinking and feeling. I think you hint at this, but I was wondering if that’s what you actually mean?