[Reposted from old comment system, from Mike A on Fri, 25 Sep 2009 21:35:22 0000]
Something I'd always instinctively felt, but it's nice to see some stats behind it. I don't find it surprising that _short fiction _SF tends to lack IP concerns - when IP conflict isn't your main focus, economy demands the editorial scalpel.
One SF novelist who's good on interpersonal stuff is Philip K Dick - it's always there, right from the outset. In _Do Androids Dream..._ we start with a vivid snapshot of Deckard's dysfunctional relationship with his ex-wife, even though she never appears in the book. There are countless other examples. He often uses the treachorous female archetype (eg Rachael) that seems to come from film noir.
As well as male-female relationships, Dick is good at employee-employer relationships: very often his classic "little guy" protagonist is drawn into the conflict of the story by his alpha-male employer - who himself is typically in conflict, due to a tangled relationship, with another alpha.
I think it's interesting that one of Dick's biggest influences was Ibsen. Ibsen's plays are built solidly on interpersonal relationships.