The Hogwarts Sorting Hat, a core part of the Harry Potter mythos, has become one of Western culture's best-known psychological tests, bigger than Myers-Briggs or whether you're a Carrie. It's inspired real-world personality quizzes at BuzzFeed, Pottermore, the Guardian and many other sites. Recently TIME Magazine developed a sophisticated Sorting Hat quiz based on psychological measures such as the Big Five personality traits.
At Hogwarts, Sorting Hat results have massive consequences, determining a student's social and sporting life, academic track, and career. Can any psychological test, applied at such a young age, accurately place every student? Or is the Sorting Hat, like the scientifically dubious Myers-Briggs, pigeonholing people with reductionist pseudo-psychology? I asked Dr Ali Mattu, clinical psychologist, Harry Potter fan, and host of YouTube's The Psych Show, whether the Sorting Hat is given too much authority. His analysis:
I have zero issues with the Hogwarts Sorting Hat itself. I'm all in on the idea of a sentient hat that uses Legilimency mind reading to understand the thoughts, values, and wishes of a first year Hogwarts student. It fits in with the magical psychology of Harry Potter, how thoughts can be manipulated through the mind-control Imperius Curse and the memory extraction spell. But the way Hogwarts sorts students into houses is a horrible way to run a school.
Your brain, your values, and your personality, they continue developing into your 20s, and there's some evidence your personality continues to change at specific times in your life. We have no way of knowing if someone is going to be primarily brave like a Gryffindor, loyal like a Hufflepuff, wise like a Ravenclaw, or cunning like a Slytherin at 11 or 12, the ages of first year Hogwarts students. At that age, young quiet and shy me would have been sorted into Hufflepuff but 20 year old confident young adult me would be more of a Gryffindor. Now? Career ambitious me is a total Slytherin.
The Hogwarts sorting ceremony sends a dangerous message to students -- who you are is fixed. The reality is when you believe your abilities can change and you're in a supportive environment, you can change who you are. This is called a growth mindset. At Hogwarts, the Sorting Hat sends the message, "This is who you are, this is who you will be, and go be with others just like you." A kid who struggles with reading, gets rejected from Ravenclaw, and is sorted into Gryffindor might begin to believe they will never be a great student and should just pursue more physically intensive career paths.
The sorting ceremony also becomes a self-fulfilling prophecy. From Milgram's obedience experiment to the Stanford prison study, there's a long line of psychological research that says situations are powerful and we take on qualities that are expected of us. Slytherins will become more cunning because that's what's Slytherins do. Gryffindors will take more risks because that's part of Gryffindor history and is what's encouraged within the house. That's probably why Neville Longbottom transformed from a timid first-year Gryffindor into a brave leader of Dumbledore's Army in book 7. This is also how business students get good at entrepreneurship, why lawyers are so detail focused, and how physicians are amazing diagnosticians.
Keeping students segregated by houses reduces creativity. We know that teams are most creative when people with different backgrounds come together in a place where it's OK to disagree. Grouping students into different houses based upon their qualities, and encouraging them to stay segregated, increases the chances that these students will think the same way, suggest the same solutions, and struggle to understand the perspectives of people who are different than themselves.
If I were the Hogwarts headmasters, I'd still use the Sorting Hat and have four houses, but I would ask it to make sure each house has students that represent all the qualities that makes people successful in life.
As for TIME's test, the Big Five is a great measure of personality, as long as people remember it reflects your personality right now. Personality changes across your lifespan, and the idea of being sorted into houses based upon this test (no matter how accurate) is a problem. People associate the house that they are in as a permanent thing, and those houses are associated with strong personality qualities. Another issue here is potential social desirability bias, answering questions in the way you think others would improve. It's pretty easy to figure out what the questions are for each house. So if you really want to get sorted into one or another, it's easy to make that happen.