That belief may persist in part because earning a good grade in a college course isn’t necessarily a student’s reason for taking an AP class in the first place. A young person might take an AP class in high school so she can skip a similar course in college or bypass a subject entirely. But getting at what drives students to sign up for certain courses, advanced or otherwise, was beyond the scope of this research.

While the authors were able to look at the first college class students took in a subject, it wasn’t clear whether the students had received college credit for doing well on an earlier AP exam. So if a student took a chemistry class in high school and then took Chemistry 101 as a college freshman and earned the same grade as another student in the class who had never set foot in a high-school chemistry course, the authors’ conclusion that high-school coursework doesn’t predict college success makes sense. But if a kid took AP Chemistry in high school and then jumped straight to a sophomore-level chemistry class, whether that kid earned a better grade might be less relevant than the fact that the high-school class saved him time and money by allowing him to skip ahead in college. And there is certainly variation in how teachers teach and what gets included in, say, AP biology classes, meaning some advanced classes are likely more beneficial for students than others.

Hershbein insists that he and Ferenstein aren’t arguing against sophisticated subject matter for kids who are ready to handle it. But the duo warn that the push to get more students into advanced classes is no definitive way to make sure students are prepared for college; it could ultimately harm kids who haven’t been adequately prepared for the material. “That’s not some sort of panacea where all of the sudden they will be college ready,” he said.

Instead, the pair thinks that if high schools want to prepare students for college, they should focus less on specific content and more on critical thinking and reasoning. Most students will forget the specifics of, say, mitosis shortly after they take their AP biology exam, but they might retain the broader concepts of conducting an experiment and presenting evidence. “It’s really the underlying skills that stay with people,” Hershbein said. That may be one reason that calculus seems to be the one exception in the research, where students who have exposure in high school benefit “mildly” in terms of better college grades. That’s “probably because it is based on cumulative learning to a greater extent than other subjects,” the authors note.

While Hershbein and Ferenstein argue somewhat bluntly that high schools are currently teaching the “wrong things,” they note that, in theory, the Common Core’s relatively new emphasis on argumentative writing and reasoning (showing how you reach a conclusion, instead of simply stating what the answer is) could be a positive shift in the way students learn. But Hershbein thinks it’s too early to tell what the long-term impact will be and that the somewhat botched roll-out of the standards has dampened the public’s perception.