Much like we suspected, the assumption that Slytherin is the "evil" house is a bunch of garbage -- remember Severus Snape, bro? AKA "one of the great heroes of the series," as Granger refers to him?

In fact, according to Granger, the misconception that Slytherin house is evil came from two things -- A, Rowling's own value system, and B, the need for Harry to have a foil (in the form of Draco Malfoy), which is a longstanding schoolboy novel trope.

"They're just ambitious," Granger told MTV News over the phone. "It’s not a quality which is considered a virtue by the people who write the books... "[Rowling's] big thing is courage, not self-interest. [When] we start off the stories, we’re being taught to sympathize with Harry... Then we meet Draco Malfoy and he’s a little git; we just intuitively despise him. That’s the necessary foil in every school boy novel. Because Draco Malfoy is in Slytherin House and he’s got Crabbe and Goyle with him, everything we see... bleeds through that filter."

However, Granger says it's important to remember that even despite Rowling's distaste for the purely ambitious, she still gave some small shout-outs to decidedly un-evil Slytherin characters.

"We get people like the potions teacher, who tried to discourage Tom Riddle from exploring horcruxes, [and] tried to help Harry -- he comes back in the Battle of Hogwarts at the end with Slytherin helpers and stuff."

So there you have it, folks -- just because you're wearing green, doesn't mean you're evil. Moving on.