>I do find him very cold-hearted to be so almost indifferent to people he grew up with. We don't know how old he was when his mother died, but his half-sisters and their mother were certainly part of his life for much longer than she ever was.

Yes, and this week a statement that Marianne makes gives us a little bit of info: "Of John I know very little, though we have lived together for years; (but of Willoughby my judgement has long been formed)." So, it seems he was in the home quite a bit and if Marianne's observation is to be trusted, he must have been distant and not very forthcoming as a boy/young man.