What's the point to the houses?

Question

In universe, students are sorted into houses based on their qualities. But when Harry Potter was sorted he was told, "He would do well in Slytherin." The question is why? There doesn't seem to be specific classes or instructors just for the specific houses. While you could assume there would be mentoring or tutoring not in classes within each houses dorms, the fact that those students would have came up in the same house system and not have any different training other than that afforded all students. Also the mentoring or tutoring isn't really acknowledged.

Why would any student develop differently in any house, other then being affected by like personalities and qualities?

Answer 1

The house system is a British thing and has been used in English boarding schools since at least the mid-18th century.

Like numerous things at Hogwarts, it's presumably copied more or less directly from Rowling's own school experience (For example, the OWLs are obviously an expy of the old Ordinary Level testing) with no real explanation given, as it was written for a British audience, who would already be somewhat familiar with the concepts and thus wouldn't need them explained to them.

Answer 2

Originally the houses at Hogwarts were created because each of the founding members had a preference for what kind of student they would like to teach. Ravenclaw wanted the brightest, Gryffindor wanted the bravest, Slytherin wanted the most ambitious, and Hufflepuff was willing to take anyone left over.

As is common in England, the houses also formed a primary social group and developed into opportunities for competition. This included the sport Quidditch and the academic point system.

As far as an advantage of being in one house or another for teaching purposes, there doesn't appear to be one, because as noted in the question teachers are spread across all houses. There might be an advantage to have one head of house over another. McGonagall was advantageous to Harry on a number of occasions (allowing him to play Quidditch, giving him rooms to practice in). All of the heads of house are presumably mentors to their students, so if you had a preference for one, then being in their house would be to your advantage.

Answer 3

Forgive me if this has been said already, but I didn't see it in the above answers (might have missed it). I think the importance for houses, besides the initial reason for the founders wanting to teach specific kinds of students, and promoting competition, is what Mcgonagall says to them in the Philosopher's Stone. "She says that the houses will be like your family"

It's important in a boarding school that you still have a "family". Your friends are more than just your friends, they are like your brothers and sisters, and your head of house (in Hogwarts, at least), is like your stand-in parent. They mentor you, discipline you, etc. https://www.boardingschoolreview.com/blog/teaching-in-a-boarding-school In the first paragraph, they say

Boarding schools are self-contained communities. Students and faculty eat together. They share relaxing times watching TV and playing games together. That is because teachers and staff in a boarding school function in loco parentis. They take the place of parents literally and figuratively. They play a powerful role in shaping and guiding their young charges while they are at school. Because the students cannot escape at the end of classes, they cannot avoid the strong influence teachers have on them

and so sorting based on traits helps foster this familial relationship. You are putting like-minded kids together who are most likely to get along. Malfoy and Harry, for example would probably have never gotten along due to cultural and personality differences. My evidence is that before Harry was even sorted, he did not like Malfoy. It also helps build strengths like others have replied.

Answer 4

The sorting hat explains the split between the houses in its song in chapter 11 of Order of the Phoenix:

Said Slytherin, "We'll teach just those
Whose ancestry is purest."
Said Ravenclaw, "We'll teach those whose
Intelligence is surest."
Said Gryffindor, "We'll teach all those
With brave deeds to their name,"
Said Hufflepuff, "I'll teach the lot
And treat them just the same."

After that the hat goes on to state that the houses should work together:

Still I wonder whether Sorting
May not bring the end I fear.
...
And we must unite inside her [Hogwarts]
Or we'll crumble from within

As to why Harry would do will in in Slytherin?

Harry's father James is from an old wizarding family that goes way back.

And (bigger spoiler)...

Harry is also carrying a shred of Slytherin's last descendant's soul.

Answer 5

The sorting hat said he would do well in Slytherin, because when Voldemort tried to kill Harry when he was a baby, and gave him his famous scar, he unwittingly transferred special gifts and powers to him as well, such as the rare ability of being able to speak Parseltongue. Voldemort himself was a descendant of Salazar Slytherin, one of the founders of Hogwarts School of Magic. The book implies Voldemort inherited that trait from his ancestor, Salazar Slytherin, therefore that is why the sorting hat mentioned that Harry would do well in Slytherin. Because Voldemorts powers and gifts were unwittingly passed on to Harry in the attempted murder, which resulted in Voldemor giving a small part of himself to Harry, making Harry an actual "horcrux", for Harry held part of Voldemort's soul. This resulted in Harry having rare gifts and abilities that Salazar Slytherin himself had, and held in high esteem, and that is why the hat said he would do well in Slytherin. Additionally, "blood purity", meaning having two magical parents, was a desirable trait for the house of Slytherin, due to the man's mistrust of "muggle born" or "mixed" marriages between a muggle and a witch or wizard. Many of these facts were revealed in the final book of the series, by J.K. Rowling entitled "Harry Potter and the Deathly Hallows".