Er, um, uh.....WHAT?!?!?!?!??!?!?!?!?!?
Elijah Bailey the New York megacity detective in the robot novels is the only fleshed out character in any of his books. And I've read all of them.
Maybe 20,000 years later, Golan Trevize Foundation councilman, who's got his cantankerous perma-batchelor skeptic attitude? Even then he's pretty one dimensional.
Hari Seldon? You'd think he'd be important. Nope vanilla. Just kind of carried along by events.
I'm not saying there's NONE for his characters, but it's still pretty damn flat. Whatever character development you THINK you read in Asimov's stuff, you probably projected yourself.