Awww, thank you so much! That means a lot. :3
Pettigrew being sorted into Gryffindor isn’t just a source of consternation for fans—I mean, even characters in canon are baffled by it, constantly citing him doing things out of fear, and generally being a cowardly, worthless individual. None of the characteristics we see in him seem to remotely match Gryffindor.
There’s many that go straight to the “sort to soon” line that Dumbledore provides—and that’s the easy answer, that Peter is a victim of being sorted at an age before his personality is expressed. But I find that people often use that line as a method of re-sorting characters they disagree with (which, 9 times out of 10, truly do belong in that House, it’s just that their comprehension of the House’s traits are shallow), and that it’s an easy out. (How did Crabbe & Goyle end up in Slytherin, would could ask? Etc.)
Whether or not personality is fixed is certainly still up for debate psychologically, and recent studies point to personality plasticity after age 30—however, these studies use Big 5 traits as their axes, and while I’m not nearly a psychologist, there’s more to our brains than just our levels of warmth or optimism. From the child development courses I took in university, there’s a lot of evidence to suggest that our cognitive functions, and our basic methods of operation, are set. A standoffish child may develop into a warmer, kinder adult, but their personality hasn’t fundamentally changed; there’s simply much more to us than that.
So, when it comes to Peter, I think that Peter was genuinely a child with a Gryffindor temperament. There’ve been other characters who, at first glance, seemed not Gryffindor—Neville is a fantastic example of somebody who started out everything that Peter seemed to also be. The difference is that Neville ultimately fell in with people who encouraged him, who helped him break out of his shell, who let him discover his own best qualities.
And while I love the Marauders as characters, let’s be real: Sirius and James were not exactly the best role models. And while it’s certainly not their fault that Peter became what he did, we don’t get the idea that they really liked him as much as they liked having a die-hard fan. They brought him along for their bullying sessions. His name might be on the map, but in everything we get about the friendship, it was a bit of a trio and a footnote. James and Sirius were definitely fans of themselves, and having somebody hang around who was more than happy to prop up their egos? They’re not going to shake that.
We don’t know what Peter’s home life was like, but even a lion if caged from birth will not fulfill its nature. From everything we can glean of Peter, he wasn’t really given a lot of positive reinforcement. Neville too wasn’t—but at the same time, his fathers were Aurors who had been tortured to insanity. At least he garnered sympathy. His teacher’s frustrations with him were often softened.
But Peter likely had no such luck, it seems, and we know from McGonagall that at least she thought of him as untalented and stupid. And while she might not have let that show in class, it seems that nobody saw any great potential in poor Wormtail.
So even if you have somebody who has the capacity to be brave, to be noble, to have honor and valor, and don’t groom them to be that, they might not. Being Gryffindor doesn’t make you impervious, and those qualities need as much nurturing (perhaps more?) as the other houses. Neville had to work incredibly hard to become who he did—and ultimately, part of what made him so brave was being willing to confront his constant insecurities and failures and rise above them. But he also had help.
And that’s not to blame Peter’s outcome all on others. We’re ultimately masters of our own destiny and there’s a lot of characters in HP who had terrible circumstances and became something in spite of it. But if you take a kid and never really allow him to reach his potential, especially if he has some pretty massive weaknesses on top of it, it’s easy to see why when the wizard-version of Hitler comes calling, he’s not going to have the bravery to back down. He’s going to cave, because what else has he done besides follow around great wizards and do his bidding? It’s just that he traded a set of heroes for villains. But when you’re weak, power is power. It’s something to follow.
The Sorting Hat takes choice into account. “Please, Gryffindor” gets as much weight as “Not Slytherin.” I always imagined that young Neville sat on the stool, begging the hat to be in Gryffindor, because if you’re told you are something, maybe you’ll be that something, and maybe Peter did the same. Maybe young Peter just really wanted to believe that he was brave, good, noble, impressive—and wanting to be something is often the first step to being it. He begs the hat for that House that will allow him to be what he wants, and he’s granted it—but fails to, and is failed by those around him, take advantage of that.
A seed is just a seed. Water it, tend it, it blossoms. Drown it, trample it, it dies. The outcome doesn’t change the start.
(It’s also worth stating that while it’s not what we’d term brave, the things that Peter does did take a pretty big pair of balls. Telling your friends you’re abandoning them for the dude that’s, like, killing everybody? Abandoning somebody you loved and knowingly causing their death? Going into deep cover for y e a r s? It’s shitty, but it’s still brave—and that brings up an interesting thing about House traits and what they really mean, but that’s another post for another day.)