Character Arcs

Klute presents a complicated character arc, from numb professionalism to feeling person, though one that could be compared to Jan Morrow's in Pillow Talk, who must also allure a reluctant male into a relationship/sex (only implied of course in the latter film).  Jan isn't suffering from the same numbness that Bree is, but both are prefer their single state.  Somewhat counter to expectations, Jan seems perfectly happy alone, while Bree seems alienated and lonely.  Further, both conclusions are implied rather than explicitly shown.  With Pillow Talk, the conclusion is unmistakable for the time since we hear Brad (Hudson) is "pregnant";  with Klute we're left to decide for ourselves if Bree can control her self-destructive nature and Klute can be flexible enough to accommodate her.     The key is that both films present the growing strains of changing gender roles/rules for both men and women.  It's also significant that it begins much earlier than many might assume--not in the seventies, but by at least the late fifties, if not earlier (women had been working in significant numbers ever since WWII).
   As I mentioned, some categorize this as a film noir (if we assume noir can be considered a genre outside of a particular historical period).  I think it's more accurate to consider a noir woman's film (an oxymoron perhaps but it's not without precedence, as Mildred Pierce demonstrates)--or at least that's what it became when Bree Daniels became the focus of the film.