It may be self-serving for a test maker to produce research showing that high school grades are rising and less reliable. Yes, it’s a justification for why high schoolers shouldn’t be freed of onerous college admissions tests, but it’s also more evidence that grade inflation is significant and worth closer attention.

The latest is an analysis of more than 4 million high school seniors who took the ACT from 2010 to 2021. ACT’s researchers calculated that the number of test takers with an A average surpassed the number of B students after 2016. Today, A students make up a majority of ACT test takers, some of whom are not college bound and take the test as a required high school assessment.

As grades rose, achievement fell. These recent A students, for example, posted lower ACT scores than A students from a decade ago. Achievement declines were seen across the board among students scoring in the middle and bottom too. That’s a worrisome sign that today’s students aren’t better or harder working and more deserving of higher grades. 

“Even after accounting for all these other factors, we still see evidence of grade inflation,” said Edgar Sanchez, a researcher at ACT who presented his study in April 2022 at the annual meeting of the National Council on Measurement in Education (NCME). “Something interesting is happening in 2016. At that point, the rate at which grade inflation occurs really increases considerably.”

One drawback of the study is that it relies on self-reported grades that students disclose on an optional survey when they register for the ACT. Students could lie, but it is unlikely that lying has suddenly increased so much in recent years that it explains the rising grades. 

Another bad sign is that the grade inflation detected by ACT closely mirrors Department of Education research. In a study of actual U.S. high school transcripts around the nation, grade point averages climbed 0.11 points from a 3.0 – a B – in 2009 to 3.11 in 2019. That study ended just before the pandemic years when ACT researchers detected the fastest grade inflation. Just as ACT scores declined, so did 12th grade math scores on the National Assessment of Educational Progress (NAEP), a national achievement test. The grade inflation prompted the head of the Institute of Education Sciences, the research arm of the Department of Education, to post a warning on the agency’s website, “Education Runs on Lies.”

Rising grades are not a new phenomenon. Research detecting sporadic bursts of high school grade inflation dates back to at least the 1970s. The College Board, which administers the SAT, has also documented grade inflation by comparing SAT scores with high school grades. A 2017 study by a College Board researcher found that grade inflation was worse at wealthier schools. 

In the new ACT study, high school grade point averages (GPAs) climbed 0.17 points from 3.22 (a B) in 2010 to 3.39 (a B-plus) in 2021. Grade inflation was fairly modest during the first half of the 2010s and began to take off after 2016. High school grades skyrocketed between 2018 and 2021, jumping a full tenth of a point as many schools struggled to grade students during the disruptions of school closures and remote learning.

At the same time, the average ACT score decreased by almost a point from 21 in 2010 to 20 in 2021. (The top score is 36.) For any given ACT score, student grades rose. For example, a student who scored a 25, which is among the top 25 percent of test takers, had an average GPA of 3.5 in 2010, but a 3.7 in 2021.  A student with a solid B (3.0) average was likely to have an ACT score of 19 in 2010, but only 15 in 2021. 

ACT researchers considered that the mix of high school seniors taking the ACT changed over the decade and checked to make sure that wasn’t confounding the analysis. But after controlling for student and school differences, grades still rose among students in each family income bracket, poor and rich alike. Black, Hispanic, white and Asian students all earned higher grades. Grade inflation happened at both high poverty schools and more affluent ones. (Depending upon the calculation, grade inflation was sometimes seen to be higher among Black students than white students, and sometimes seen to be higher among schools with more affluent students.) 

The ACT study didn’t factor in bonus points that high schools award for Advanced Placement or International Baccalaureate classes. That means grades topped out at 4.0 and grade inflation was not detected among the very highest ACT scores, which clustered at 4.0 for the entire decade.

It’s not clear exactly what happened in 2016 that prompted so many high school teachers across the nation to hand out higher grades. But I wonder if grade inflation could have been an unintended consequence of the test optional movement, which gathered steam in 2016 as more than 900 colleges dropped the requirement to submit ACT or SAT scores in applications. The vast majority of colleges subsequently went test optional during the pandemic to accommodate students who were unable to sit for a college exam. As a result, college admissions officers relied more heavily on both grades and advanced coursework to make decisions. 

Previous academic research had shown that college admissions tests weren’t a strong indicator of college readiness and that grades were much better at predicting which students would do well, and could help increase diversity on campuses. This research, along with the expense and stress of test prep tutoring, inspired many colleges to drop the exams. However, the anti-testing research was conducted before the recent escalation of grade inflation and it is unclear whether grades will still be a good indicator now that As are more plentiful.

This story about grade inflation was written by Jill Barshay and produced by The Hechinger Report, a nonprofit, independent news organization focused on inequality and innovation in education. Sign up for the Hechinger newsletter.