Janie's "Idealism"

Janie's life seems to be unfolding in a progression that is similar to the narrator's from Invisible Man, but very different in both beginning and goal.  She has a naive (at least from the perspective of her grandmother) expectation of what love and men should be, just as the narrator has a naive expectation of what the path to success in the world will be.  Both stories are also large frame narratives, although I think we have a little less understanding of what changes Janie has gone through, whereas the personality differences between the narrator in the prologue and the first chapter are very stark.

The subject matter seems lighter than Invisible Man so far; Janie hasn't really had any strong confrontations with other characters yet, and it even seems that her naive ideal about love may be a thing of the past soon.  This leads me to believe that either the novel will take a sudden darker turn, or Janie may hold onto her ideals and give up secure situations to pursue "adventure".  Then the final question posed to the reader would be something along the lines of "was her 'adventure' and pursuit of ideals worth the less favorable final result?"  I think it might actually be a more interesting novel this way, often tragedies in novels feel contrived or just out of place.  At the same time I don't really think Janie has been established as a particularly unique or compelling protagonist, albeit being independent in many ways, so this plot-line could become boring.  

The Narrator's Max?

Something I noticed after completing Invisible Man was the complete lack of any characters that sympathize with the narrator or have an honest interest in his success.  Bigger on the other hand had both Max and Jan, although they didn't truly understand his psyche until the end of the novel.  When Bigger first met these characters and others, he was either suspicious or outright angry, unlike the narrator, who was very trusting and eager to please.
It may be that this difference is due to the motivations of the protagonists.  The narrator is more concerned with the disillusionment of his preconceptions of his environment while Bigger is trying to carve out his own personal identity.  Therefore Ellison is more concerned with the roles in the environment that his secondary characters play rather than their actual relationship with the narrator.  Native Son is a lot more about Bigger's psyche in contrast to that of what we see as weak-minded individuals.  He is able to pursue his own "accomplishment" in a way that transcends the environment, not particularly interacting with it in anyway.  This is of course evidenced by his complete lack of understanding of Max's speech in the court.  Even in the end when he embraces Max and Jan as something close to friends, it's on a very personal level, independent of the roles each character might play.  The narrator in Invisible Man, for all his resent of being labeled, only really views other individuals through the roles he expects them to fit into.  This is likely a result of the narrator's preconception of having to find success by following the rules of the system.  Was Bigger able to find personal accomplishment because he had no pre-existent illusions of what success meant?  This could be a topic that Ellison and Wright disagree on.

The True Naturalist

The Invisible Man has a somewhat opposite protagonist dynamic to Native Son.  The narrator starts out (in his life, not the novel) as a fairly average character, albeit perhaps especially submissive and naive.  He is certainly not an unrealistic or extreme character that many would label Bigger as.  On the surface, this makes him seem more relatable than Bigger was at the opening of his story, but ultimately his lack of depth ends up making the reader feel more distanced for most of the novel.  However the narrator changes drastically from this almost lack of personality to an extremely eccentric, analytical, and probably insane character by the time the epilogue rolls around.  This somewhat blank slate was formed into something very complex through Ellison's very detailed and maybe absurd environment.  Bigger however quickly evolves into a unique, impassioned character that I at least found to be relatable on a very human level.
I already wrote a blog post (and response paper) on why I consider Native Son to be more of an existentialist novel than a naturalist one; I find The Invisible Man a better fit for this category.  Ellison doesn't really care whether the reader finds the narrator to be an interesting character, just that the premise of the character is believable.  From there Ellison uses his symbol-ridden environment to mold him, thereby accomplishing his social commentary on the visibility/invisibility of an individual in society (or whatever you think he is trying to say, because really, who knows).  As others have pointed out, Ellison wants the reader to be able to imagine themselves in the narrator's position.  Regardless it seems clear that Wright is more concerned with existentialism, as evidenced in Bigger's final words, and the general lack of blatant symbolism, instead favoring character interaction.  Ellison seems to be more resigned to the power of naturalist influences, and only has ambiguity in what exactly he is using his naturalist ideology to point out.

As an aside I'd like to say that my opinion on The Invisible Man has changed, and I found the ending to be really satisfying.  I'm not saying I enjoyed it as much as Native Son, but I like that Ellison is able to portray naturalism in a non-pessimistic way as the novel closes.