I was watching the first spiderman movie and I wanna talk about it for a second.
I'm pretty impressed with the character work in this movie, especially for a superhero movie at it's time.
Most superhero films didn't take time to develop the villain with a character arc at the time. But this movie does.
Some of the only other main other examples I can think of that's done this is Joker in TDK and Loki in Thor, not counting Raimi's other spiderman movies of course. The villain in superhero movies is usually just the villain. In all superhero movies from Batman 1989, Batman Returns, Batman Forever, the superman films, even in more recent films from Marvel, the villains don't have character arcs.
But this movie paints a pretty interesting picture for Norman's development as a father. He blows off his son for an admiration of Peter, who he looks at because of their similarities. When he finds out that Peter is spiderman, Norman even resists the goblin with Peter. Who knows what the goblin would have done otherwise? But Norman isn't really willing to go directly after Peter. Even as Harry comes to him broken hearted it doesn't seem like Norman's actually really figured out what to do about Peter yet, beyond scaring the crap out of his aunt.
Until he sees how hurt his son is. And finds out the betrayal that Harry's felt. Harry tells him about Peter's feelings for Mary-Jane and for a second he thinks about what he could do with it. But something clicks with him about how hurt Harry is. That's when Norman realizes that his son's been hurt and there's this change in what his priorities are.
It's interesting because Norman and the goblin have been separated the whole movie, by goals, by actions, even by space (that scene in front of the fireplace seems to emphasize a gap between Norman's body and the goblin's brain or head as it were, a gap between what Norman wants and what the goblin is telling him to do, with Norman being reeled in by the goblin, being pulling under his control, physically and mentally, until Norman is on the goblin's side of things). But in this moment, Norman and the goblin align for a singular purpose: Destroying Peter. They have different reasons, sure, but in this moment, where Norman was resisting the goblin before, he lets the goblin off the chain. Allowing him to do anything, even get the person that is a part of the reason Harry is heartbroken: Mary-Jane. Apart of that certainly seemed to be Norman getting revenge on her for Harry, while the goblin just wanted to use her to get spiderman.
There's a bit of a parallel here between Norman and Peter in spiderman 2. In spiderman 2 Peter is in conflict with the spiderman part of him. Peter wants a life, with school, with his friend, with Mary-Jane. But spiderman's purpose is to be a hero. They can't work together because what they want conflicts with eachother, so Peter and spiderman butt heads and this manifests itself with his mind rejecting the powers his body has. His powers only work when the two are aligned. That's what happens at the bank. His powers are easy and free flowing, especially after ock takes aunt may. And it's what happens at the end when ock takes Mary-Jane. Peter and spiderman's goals are aligned. They don't conflict with eachother. Peter wants to protect his loved ones and spiderman wants to stop ock.
Anyway, back to Norman. It's all in Norman's arc. He becomes someone who is able to think and care about his son's feelings, even right to when he dies with his words to Peter, it's all about Harry for him: "Don't tell Harry." That's a very character, human moment to leave Norman on. It played into his character arc nicely.