Can houses have stereotypes?
Well the fans, at least have IMO, managed to make a stereotype for a couple of houses, Hufflepuff Slytherin and maybe Ravenclaw.(Although Slytherin's stereotype actually did come from the book)
Slytherin's came from the book and it's heard a lot, and that is all Slytherin's are bad.
Hufflepuff's is that they are all idiots and are completely useless. (Ironically a lot of this comes from people who cried when Cedric died)
And Ravenclaw I've heard a few times but it's not a được ưa chuộng one but some people think they are snobby.
I am sure Gryffindor has one too but I have yet to hear one.