Brown Professor Exposes Mass AI Cheating After Exam Scores Plunge from 96 to 48

"We cannot choose to become idiots": The AI cheating scandal roiling Brown University

Ivy League college students are, by definition, intelligent. They don't need to use generative AI to cheat on exams; they could just learn the material. But they also tend to be competitive, ambitious, and overscheduled, so AI can look like an easy shortcut that makes more time in their lives for things that can't be done by a chatbot. When the pressure is on, which approach do they choose? A new scandal at Brown University reveals that huge numbers of these students are likely to cheat. Record scores A recent survey of Princeton students found that 29.9 percent admitted to cheating with AI on at least one exam or assignment. But the recent situation at Brown gives us a better sense of what this kind of cheating looks like in one particular class -- and just how much it may be substituting for actual learning. And we know all this because the blind economics professor at the center of it all, Roberto Serrano, is not letting it go. In just the last week, Serrano -- who was born in Spain -- has told his story to El País and Inside Higher Ed, which have both run significant pieces on the scandal. The story that Serrano told them begins in December 2025, when a gunman attacked Brown's campus and killed two people, including one who had recently introduced herself to Serrano. Shaken by the experience, Serrano decided that his spring 2026 section of the quite difficult ECON 1170 would allow take-home exams for both the midterm and the final. Suddenly, the course received an influx of students. El País has the story: The course... typically attracts few students, but very good ones. [Serrano] has never had more than 30 students enrolled at a time, and on some occasions he had only eight. This semester, probably because of the new evaluation system, 86 students signed up for the class. The results of the midterm exam, which was administered on March 5, were extraordinary, with an average score of 96 out of 100. Forty students scored a perfect 100. This was indeed extraordinary, because as Serrano told Inside Higher Ed, "Historically the average grade in the midterm of this course has ranged between 65 and 80 [percent], and this exam was harder than the exams I wrote in the past, because... take-home is an opportunity to challenge the class a little bit more, given that you're giving the students unlimited time." Beyond the numbers, many of the answers, even when correct, felt slightly off. They had a "very convoluted style," Serrano said. When he and his grad students ran the exam questions through ChatGPT, they received similar results. A suspicious Serrano decided that he would make the final exam in-person; he would see if students did similarly well on it. He emailed his class, telling them, "I am not declaring [the midterm] void for now. I am going to give the class a chance to prove me wrong. That is, if the distribution of the final exam is roughly similar to the distribution of the midterm, I will count the midterm. Otherwise, which is of course what I expect to happen, I will declare the midterm void and reweigh the final accordingly." Eighteen students suddenly dropped the course, while nine others didn't even attend the final exam. Of those 27 students, El País noted, "22 had scored a perfect 100 in the midterm exam." Among those who took the test, the average score plunged -- from 96 all the way down to 48. A failed society? The professor was horrified by what appeared to be massive cheating in his course -- cheating that was preventing most of the students from learning the material. Serrano comes across as someone with no inclination to coddle elite students. His attitude may be traceable in part to his own childhood, in which he went blind from retinal dystrophy at age 17 and had to make a choice about what the rest of his life would look like. From El País: After a short-lived crisis, he decided [blindness] would not stop him. He learned Braille, and his excellent academic record opened up the doors of Harvard. "Of course it affects my life, but one shouldn't over-dramatize. We economists understand reality as a set of people responding to optimization problems with restrictions. I view my disease simply as one more restriction that I have to deal with, and I optimize based on that," he says. As a university, Brown is grappling with hard questions about AI use at the moment. It recently released a provost-led report (PDF) on "Generative AI in Teaching and Learning," which found that it's not just professors who have concerns. Even though "56 percent of undergraduate respondents [at Brown] and 67 percent of graduate and medical student respondents reported intentionally using GenAI tools daily or weekly," the report notes that large majorities of students also have "concerns about the impact of GenAI use on their learning" and a "fear of negative consequences for their cognitive capacity." Serrano shares those concerns, and he wants universities as a whole to stand up for human thought. That's why he's not letting this story go, despite what he contends is a fairly tepid reaction from Brown administrators. "We cannot afford to have a society in which a significant fraction of our best young minds think that cheating is okay," he told Inside Higher Ed. "That leads to a declining society, to a failed society. "We cannot choose to become idiots."

A Brown professor's proof of mass AI cheating

A Brown professor let his class sit take-home exams. The average hit 96. Then he made the final in-person, and the score crashed to 48. The gap, he says, is a warning about what AI is doing to learning. An economics professor at Brown University suspects most of his class cheated with AI, and he has the numbers to make the case. Roberto Serrano watched his take-home midterm average hit 96 out of 100. When he switched the final to an in-person test, the average fell to 48. He has taken the story public, telling El País and Inside Higher Ed that he will not let it go. The take-home format came out of tragedy. After a gunman killed two students on campus last December, many said they felt anxious sitting exams in a room full of people. Serrano offered take-home midterm and final papers to ease that. The irony stings: the one time in decades he relaxed the rules, much of the class cheated. The numbers that gave it away Serrano's course, ECON 1170, is an advanced undergraduate economics class that usually draws a small, strong group. He had never taught more than 30 students, and once had just eight. This term, 86 signed up. The new take-home format likely drew them in. The midterm results were, in his word, extraordinary. The class averaged 96, and 40 students scored a perfect 100. The historical average for the course sits between 65 and 80, and this exam was harder than usual. Take-home, Serrano reasoned, was a chance to push the class further, given the unlimited time. The answers themselves felt off. Many correct ones carried a "very convoluted style". When Serrano and his graders fed the questions to ChatGPT, they got similar results back. The test he set to prove it So he set a trap. He told the class the final would be in-person, and that he would compare the two distributions. If they matched, he would keep the midterm. If not, he would void it and reweight the final. The response spoke for itself. Eighteen students dropped the course, and nine more skipped the final. Of those 27, El País noted, 22 had scored a perfect 100 on the midterm. Among the students who did sit the exam, the average dropped from 96 to 48. By Serrano's count, at least 50 students cheated on the midterm, and he calls the evidence overwhelming. A wider reckoning Brown is not alone. A recent survey of Princeton students found that 29.9 per cent admitted to cheating on at least one exam or assignment, most of it using AI. Schools have spent two years chasing detection tools and rethinking how they test at all. Students feel the strain too. Brown's own provost-led report found that most undergraduates use generative AI weekly or daily. Yet large majorities also worry about the effect on their learning, and fear what it does to their "cognitive capacity". That worry sits alongside a broader shift, as AI reshapes who gets hired and even how people think and write. Serrano frames it in the starkest terms. Why it matters "We cannot afford to have a society in which a significant fraction of our best young minds think that cheating is okay," Serrano told Inside Higher Ed. "That leads to a declining society, to a failed society. We cannot choose to become idiots." His experiment is small, one class, one term. But it turns a fuzzy worry into a hard number. Take the AI away, and half the apparent knowledge goes with it. That is the figure universities now have to sit with.