I’m not particularly proud of this fact, but here it is: Pottermore, the Harry Potter-themed website unveiled by J.K. Rowling in 2012, has peered deep into my soul, evaluated its findings, and pronounced me a Hufflepuff.

Fans of the series will know why this is upsetting. For all the non-Harry Potter buffs reading this, though, here are three quick points of explanation. One: At Hogwarts, the wizards’ academy that serves as the backdrop for most of the series, students are sorted into one of four houses, each with its own distinctive character. Two: On Pottermore, fans can take a personality quiz to do the same. Three: Hufflepuff’s defining trait is “nice.” Its mascot is a badger. Its members, if Hogwarts were an American high-school cafeteria, would be the ones in the corner, frantically combing the trash for their retainers.

So, perhaps understandably, I’m less than thrilled by the idea that Pottermore may, in fact, have read me pretty well: In a study recently published in the journal Personality and Individual Differences, researchers found that a person’s preferred house may offer hints about his or her personality.

For the study—titled “Harry Potter and the measures of personality: Extraverted Gryffindors, agreeable Hufflepuffs, clever Ravenclaws, and manipulative Slytherins”—132 Harry Potter fans who had already taken the Pottermore quiz filled out a series of personality assessments. Comparing average scores for each house to scores for the whole group, the researchers found that, for the most part, people’s personality traits tended to mirror the stereotypes of each house: Ravenclaws scored highest on “need for cognition.” Slytherins—the villains of the wizard world—scored highest on the Dark Triad (not to be confused with the Dark Arts), which encompasses narcissism, psychopathy, and Machiavellianism; Hufflepuffs, true to form, were the most agreeable. Only the members of Gryffindor—home of Harry Potter himself, along with his gang, and all of Hogwarts’ bravest—didn’t match up to their fictional counterparts.

Beyond delighting or devastating the Harry Potter superfans of the world, though, the study also adds new support to a not-so-new idea: that the connections a person feels to a fictional group or character may shape them in ways that stretch beyond the page. In 2011, researchers from the State University of New York at Buffalo published a study examining what they called the “narrative collection-assimilation hypothesis,” or the idea that reading about a group may be enough to make a person feel like a part of it. After reading excerpts from either Harry Potter or Twilight, study participants identified more closely with whichever magical being—wizards or vampires, respectively—their passage had covered. And last year, a separate study found that children who read Harry Potter excerpts about Harry’s friendships with stigmatized members of the magical world—like wizards born to Muggle, or non-magical, parents—later displayed more tolerant attitudes towards real-life social “out-groups,” compared with children who had read more neutral scenes.

In the case of this most recent study, though, at least part of the effect may be due to self-selection. The authors also found a correlation between the personality of each fictional house and the people who reported that they wanted to be in it, regardless of where they were actually placed. Wanting to possess a certain trait, in other words, was linked to actually possessing it: People who said they wanted to be in “manipulative Slytherin,” for example, tended to score higher on narcissism, whether or not Pottermore had assigned them there. (As Hogwarts’ headmaster, that wise old wizard Albus Dumbledore, once said: “It is our choices, Harry, that show what we truly are, far more than our abilities.”)

Overall, “our findings suggest that fiction can reflect real underlying personality dimensions,” the authors wrote. “Clearly, what we read can influence how we see ourselves.”

Or, as Dumbledore put it: “Of course it is happening inside your head, Harry, but why on earth should that mean that it is not real?”