Warning: Cursed Child spoilers
I asked myself more than once when I was reading Cursed Child why Scorpius would be a Slytherin. And not because he’s a good person: I’ve thought for a long time that there must be more to Slytherin than just dark magic and evil schemes, and I love that Cursed Child explores a different side of it. It’s just that Scorpius is so obviously a Ravenclaw, and while I think he does have a Slytherin side, it’s subtler and takes a while to show itself.
Scorpius is the biggest bookworm in the Harry Potter world since Hermione, and in fact, their mutual obsession with books and knowledge is explicitly compared when they answer a question about magical history in unison and Ron groans that “there are two of them”. At other points in the story, Scorpius remembers the most common love potion ingredients and the fact that one of them burns when it comes in contact with tincture of demiguise, lectures Albus on choice of spell being “a much-underestimated part of modern witchcraft”, and generally provides the exposition on obscure magical knowledge that came from Hermione in the original series. If her intellect made the sorting hat consider putting her in Ravenclaw, it seems fair to say that he would have done well there, too.
So what about Scorpius – aside from his last name – would put him in Slytherin? Is he ambitious? Yes and no. He’s not willing to hurt others to pursue his ambitions. He is very much not interested in a world that is better for him but much worse for nearly everyone else. The alternate universe Scorpius clearly does not feel the same way, and seems to be a more typical Slytherin in that regard. But ambition doesn’t have to mean world domination. Scorpius has ordinary goals, like making his house Quidditch team and getting a date with Rose Granger-Weasley. He seems to become more ambitious as his self-esteem and confidence improve over the course of the story, and I suspect that will continue as he grows up, but that he will still use better methods than we typically associate with Slytherin to achieve his goals.
Is he cunning? In his own way, yes. His intelligence seems to be more of the Ravenclaw type; he enjoys learning things for their own sake, and sometimes the things he knows happen to be useful. However, he succeeds by being smart rather than impulsive or reckless. He’s certainly able to think on his feet: he figures out how to send a message to Harry from 40 years in the past, hides the time turner from the adults because he doesn’t trust them to destroy it, and – in the alternate world ruled by Voldemort – finds what remains of the resistance and convinces them to trust him pretty quickly. He’s also, in his own words, “a pretty good liar”, although he doesn’t lie unless he has a good reason.
But mostly, I think it comes down to the fact that he would have wanted Slytherin. Despite being very different from his father, he seems to want his approval. Being a Slytherin would have been a sure way to make his father proud, and on the flip side, I’m not sure Draco Malfoy would have been as forgiving of his son being in an unexpected house as Harry is. If his mother was also a Slytherin, that’s even more reason why he might want to be placed there. Scorpius has enough Slytherin in him for the hat to at least consider it, and if he had a strong preference, that would explain why he ended up there as opposed to Ravenclaw, where I still think he would have fit at least as well if not better.