All I know is, I'm probably a Hufflepuff. Whatever that is.

It's a proper Arena Method error - characters can realistically know only so much information. 

For HP to overcome this, it would need to have POVs from non-Griffindor characters. (Unless it does, in which case blame Rowling for unrealistic characters.)

For an example, let's look at Slytherin. Its members are depicted as varying levels of evil, when in truth, Slytherin is about cunning and self-preservation. As such, while it makes sense for the bad guys of the series to have Slytherin affiliation, it should,by its very definition, be a complex house.

Did you already forget about Snape? He was a Slytherin, and is (so far as I can tell) considered one of the unsung heroes of the whole story, and easily one of the more complex. He's cunning and ambitious, thus fitting the mold perfectly, but also incredibly loyal to Dumbledore and comitted to the cause of eradicating Voldemort. In contrast you have Malfoy who despite his bullying and confident outward appearence is basically a doormat to the forces of his father and the Death Eaters. But I wouldn't call him evil, just easily influenced.

And let's not forget about Harry Potter himself who was borderline Slytherin. I think it's even mentioned by someone (Dumbledore, or the Hat maybe) that he would have done equally well in that house. I'd have to go digging for that, though.

And then there was Harry's father, who was a Gryffindor, and was basically a bully. Which goes against the Gryffindor code of being brave and chivilrous (or something like that- I don't really remember). So there are at least two characters here who defy the expectations of their houses.

So being in Slytherin doesn't inherently make one a bad person, nor does being in Gryffindor inherently make you a good person. The books are fairly limited with their almost exclusive Gryffindor viewpoint, but in spite of that I think Rowling does a decent job with the portrayal of Slytherin house, particularly in the last few books (which is, admittedly, only when these things start to come together). Could she have been more explicit? Sure, but I'm not going to ding her writing for it.

And that's as far as I want to go for psych evaluating characters of a children's fantasy series.

This is part of the reason I just claim I'm a muggle whenever my friends talk about what house they're in. (Also, because I don't really care.)

Y'know... I wonder if there is homeschooling in the wizard community. Probably not, due to the nature of the power they're working with, but it's an interesting thought. Or exchange students. Or college. (Seriously, If Aurors have to take test after test to get a job, where are they going to learn those extra skills?)

Heck, the books hardly had any non-Harry POV sections, except for the first chapters in the last few books. None ever really followed the other students around the school. Also, I think that home schooling was mentioned once as an option, since parents took their kids out when "dangerous stuff" happened at the school, only it got made mandatory when Voldy took over.

Also, for Slytherin anyway, I can't help but feel that their beliefs had a major component, or at least heavily influenced their “self-preservation” bits.  They were all about being pure blood and hating on those who weren’t... and not to mention any Death Eaters were probably also about self-preservation because they figured, who not join the winning side?

It would’ve been nice to see more characterization on the Slytherin students in the books outside of Malfoy, because it seems a majority of the characters were Griyffindor.  And I’m sure there were some who were not pure evil, but they didn’t out themselves and go against the social norm.  Partially because they’re kids, and partially because the entire wizarding world (in Britain, at least) seemed to be stuck in a status quo with few being unwilling to stick their necks out to change things or help. (See, entire fifth book.)

Anyway, um, my point is, maybe they got the house thing together later on, but it was just really cut and dry, especially for Slytherin, in Harry’s years?  (Wow I wrote too much about this didn’t I?)

He's Hufflepuff

no doubt about it

How you can tell things aren't really that cut and dry with Slytherins: Horace Slughorn was a Slytherin (okay, bad example, but he wasn't a bad guy), as were Snape (Snape, Severus Snape. DUMBLEDORE!) and Regulus Black (RAB, who gave his life to try and stop Voldemort). Out of Gryffindor we have Peter Pettigrew (coward, traitor) and James Potter (bully), and the defining trait of Ravenclaw Luna Lovegood seems to be that she's....weird. The houses were generally depicted as being viewed in stereotypes, but there were characters who broke the mold.

It's also worth noting that some of the similarities between people of the same house could be seen as them adjusting their attitudes and behavior in order to fit in better with the house they're assigned. Frankly, this is not unheard of even in real life. In fact, it's the very essence of peer pressure.

Sure, a Slytherin kid could have a secret friendship with a Gryffindor kid, but can you imagine how much pressure there would be on them NOT to do so? How much of a risk it would be to their social credibility within their own house if they were found out?

This is particularly true considering that the Slytherin house, when the series begins, has had a string of house cup victories. They have every reason to take that tradition very seriously and embrace that spirit of fierce competition that keeps being rewarded.

Likewise, Neville Longbottom was not as stereotypically hot-blooded as people would expect a Gryffindor to be, and as such he was looked down on even by classmates in his own house. Gryffindor, as Slytherin house's classic rivals, felt a great deal of pressure to out-perform them competitively, to honor those who helped them to that goal and to ignore or even look down on those who they thought were holding them back.

If anything, it's just a reminder that the British boarding school lifestyle that the Harry Potter series seems to reflect is not some idyllic childhood experience that every kid should dream of having. Like any school, it has a dark side, and what people learn from that kind of experience is not always what the instructors and administrators set out to teach.

Naturally, as the series went on, this was explored more and more. We saw how Draco Malfoy's evil side was to a great extent him trying to meet the expectations of his parents and the others they associated with, and how he didn't really have it in him to be evil beyond the scope of a childhood bully. And of course we saw how Snape's harsh and spiteful attitude was shaped by his experiences as a Hogwarts student who was bullied by other students.