Jenny and I got into a discussion once about how so many historical novels use "helping orphans" as a shorthand technique to supposedly make a jerky hero sympathetic. I always had a mental image of rakish looking hunks lining up outside an orphanage door, checkbooks in hand. Anyway, I don't think that works! I think that readers sympathize with interesting character confronted with interesting conflicts. That is, "doing nice things to poor benighted orphans" isn't necessarily going to make him sympathetic. (And why is sympathy the reaction we want anyway? I do think "reader involvement" might more important, and allows for characters who are more or less than sympathetic.)
What I think I’m discovering is that character development sort of depends on these particular circumstances (the opening situation and then the plot events) causing a change in his behavior. If your hero already supports a dozen orphans because he's just such a doggone good guy, then his taking care of this new orphan is not only effortless (he’s got the whole system set up already), but also, in a way, nothing special. He always does that. All you’ll end up doing is showing that he’s a wonderful, charitable guy—and always has been.
Consider what would happen if he has no history of supporting orphans, and this kid shows up, claiming to be the orphan of the hero's former girlfriend. And... worst possible time... he's about to marry the beautiful and moralistic daughter of his wealthy boss, and she's righteous and jealous and boss is the Old Testament type. So the arrival of this orphan kid is a catastrophe, a conflict, not just the latest in a long line of orphans Hero has helped, but a problem he doesn’t know how to solve, but has to solve anyway. In other words, dealing with this orphan makes him grow, in compassion or empathy or generosity—doesn’t just display those virtues for all to see.
And if he’s embarrassed and mad at himself for doing the right thing, If he’s not sure it’s the right thing, and if doing it gets him into trouble, all the better.
What do you think? Maybe I’m misreading the attitude of the reading public, but I think a bit of curmudgeonly spirit, when coupled with eventually good actions, really does increase the sympathy factor.