Tools of Characterization
Characterization in Spider-Man
Actions
All the characters in Spider-Man are characterized by what they do. For example, once the Green Goblin murders Dr. Stromm, Gen. Slocum, Balkan, Fargas, and the rest of the Oscorp board, it's pretty clear that he's the villain. Good guys don't blow up bunkers and balconies like that.
His son, Harry, meanwhile, is characterized by his actions as privileged and inept. When he feels threatened by Mary Jane's burgeoning crush on Spider-Man, for example, he wants to invade her space immediately and, when that fails, offers to buy her something:
HARRY (on the phone with Mary Jane): "Incredible"? What do you mean he's "incredible"? No. All right, wait. Stay there. I'm gonna come over. No, I'm gonna come ov—all right. Fine. Will you call me in the morning, and we'll go and have breakfast and…um…I want to buy you something. Because I want to. It'll make you feel better. Okay. And what do you mean, "incredible"?
Peter smiles.
HARRY: All right. I'm sorry. Sleep tight. Don't let the bedbugs—
Mary Jane hangs up.
These are not the actions of a confident, well-adjusted dude.
Peter Parker, meanwhile, is the type of guy who's going to run into a burning building not once but twice, even while the police try to stop him:
SPIDER-MAN: It's okay. Your baby's fine.
MOTHER (at fire): Oh, my baby! God bless you, Spider-Man. Bless you.
COP (at fire): There he is! Don't let him get away! Hold it! Hold it right there! You're under arrest. I'm taking you in.
A woman screams from inside the burning building.
YOUNG LADY (at fire): Oh my god, there's somebody still up there!
The woman screams again.
SPIDER-MAN: I'm going.
Big or small, Peter/Spider-Man's actions are always heroic. He stops low-level crooks on the streets of New York. He saves Mary Jane's life three different times. He prevents a pack of schoolkids from being dropped to their watery demise in the East River, and he goes head-to-head with the Green Goblin, an honest-to-goodness unhinged lunatic, every time he rears his evil, pointy-eared head.
We don't know how he has the energy, frankly. Must have something to do with that gnarly spider bite.
Types of Being
Speaking of spider bites, both Peter and Norman are heavily characterized by the types of being that they are, which is to say, after that spider chomps on Peter and after Norman self-administers the Oscorp performance enhancers, they're no ordinary humans.
They're super humans.
Norman, for example, gains super strength and aggression. He's a little feral, too. Just ask Dr. Stromm. (You know, if he wasn't dead.)
Peter, meanwhile, can crawl up walls, shoot webs, and swing across the big city skyline like gravity just doesn't apply to him. He has super strength and even a touch of precognition.
What he doesn't have is a military-grade armored flight suit and glider like Norman. As noble and well-intentioned as Peter is, just as a man, without the changes that genetically engineered spider makes to his DNA, he wouldn't be Spider-Man.
Thoughts and Opinions
All of Peter's superpowered skills and heroic actions would be for naught without his brainy moral fortitude. He gets that sense of right and wrong from Aunt May and Uncle Ben, his surrogate parents, the latter of whom imparts to Peter a very, very important piece of advice the last time they speak:
UNCLE BEN: Remember, with great power comes great responsibility.
These are the words that guide Peter, forcing him to sacrifice what he wants for the good of others time and time again instead of, oh, we don't know, trying to destroy New York for his own amusement like a certain ill-disposed dude in a goblin mask.
The Green Goblin is characterized by his bitterness and resentment. He has next to no faith in mankind. He believes that relationships built on sacrifice end in betrayal, and he tries to make this argument to Spider-Man on more than one occasion in the film.
Here's the clearest distillation of his jaded point of view:
GREEN GOBLIN: You're an amazing creature, Spider-Man. You and I are not so different.
SPIDER-MAN: I'm not like you. You're a murderer.
GREEN GOBLIN: Well, to each his own. I chose my path; you chose the way of the hero. And they found you amusing for a while, the people of this city. But the one thing they love more than a hero is to see a hero fail, fall, die trying. In spite of everything you've done for them, eventually, they will hate you.
Ouch. Sounds like Norman is still not over his split with Oscorp. To be fair, it was a bad breakup. It wasn't so bad that it justifies becoming a homicidal maniac…but it was nasty.