Read Harry Potter, Dislike Donald Trump?

Most of the biggest fictional villains undergo a rite of passage where their names become shorthand for real-world evil. It’s no surprise then that, in such fraught political times, the references to notorious Big Bads seem to be everywhere now. Walter White. Darth Vader. The Joker. Sauron. Cersei Lannister. Patrick Bateman. Ramsay Bolton.

But rarely do such comparisons prompt the character’s creator to speak out, as J.K. Rowling did last December after repeated observations that the Republican presidential candidate Donald Trump is like Lord Voldemort from the Harry Potter books:

How horrible. Voldemort was nowhere near as bad. https://t.co/hFO0XmOpPH

— J.K. Rowling (@jk_rowling) December 8, 2015

It was a powerful statement, if notably hyperbolic. (Voldemort was a literal mass-murderer; Trump is not. Voldemort was a powerful dark wizard; Trump is just a Muggle.) But a forthcoming study from the journal PS: Political Science and Politics makes a better case for how lessons learned from fiction can influence people’s political preferences. The researcher Diana Mutz, a professor of political science at the University of Pennsylvania, found that Harry Potter book readers are actually more inclined to dislike Trump. This was the case even after Mutz controlled for variables such as age, education, gender, party identification, evangelical identification, and ideology.

Given that these typical predictors didn’t change the outcome, Mutz floats the likelihood that the lessons of the novels—embracing tolerance and inclusivity, rejecting physical and psychological violence—might explain the correlation between reading Harry Potter and disliking Trump. Basically: People familiar with the series’ narrative of good-vs-evil might recognize aspects of the books’ portrayals of “evil” in Trump. Mutz discusses how, in Rowling’s novels, the protagonists are constantly defending the outsiders of the wizarding world. “The ongoing battle between good, as personified by Harry and his friends, and evil, as personified by Lord Voldemort, is at root about the importance of group purity,” she writes, drawing connections to Trump’s statements about banning Muslims from entering the U.S., building a Mexican border wall, and other racially inflammatory comments.

The study featured 1,142 respondents. An initial 2014 survey measured their exposure to the Harry Potter films and books, and a second survey conducted in 2016 asked subjects to rate their feelings about Trump on a “thermometer” with a scale of 0 degrees (unfavorable) to 100 degrees (favorable). While watching the films didn’t significantly predict people’s feelings about Trump, reading the novels did (possibly because the mediums lend themselves differently to exploring the relevant themes of tolerance.) Additionally, Mutz notes that the delay between people’s consumption of the Harry Potter stories and their exposure to Trump bodes well for the study results, since people had plenty of time to absorb the underlying messages of the series before forming attitudes about the candidate.

It’s worth noting that the study occasionally contains editorialized language. (From the conclusion: “Perhaps most importantly, these findings raise the hope that Harry Potter can stop the Deathly Donald and make America great again in the eyes of the world, just as Harry did by ridding the wizard world of Voldemort.”) But it also, as Mutz writes, offers “some of the first evidence outside of a laboratory that a fictional story may have implications for general election preferences.” There will always be limits to the usefulness of comparing real people to fictional characters. And so far, there has been only one other empirical study exploring the political impact of reading Harry Potter (unlike Mutz, the researchers didn’t control for important factors such as political ideology.)

But it seems less specious to argue that the bestselling book series of all time could instill values that affected how its readers—especially its younger fans—now think about the world. From 1997’s Harry Potter and the Sorcerer’s Stone to 2007’s Harry Potter and the Deathly Hallows, the series consistently explored the dangers of cults of personality and authoritarianism through individuals such as Voldemort, but also Dolores Umbridge, Gilderoy Lockhart, and Rita Skeeter. It reinforced the virtues of acceptance and diversity, championing marginalized characters such as the house elf Dobby, the half-giant Hagrid, and other “non-pure” groups. Readers learned that it was was right to defend victims of discrimination, even if it meant being ostracized. While observational data can’t confirm causality, Mutz’s study nonetheless suggests that Rowling’s simple but meaningful messages have helped shape the political sentiments of her readers.