Historically, boys have outpaced girls in math and science achievement, while girls have performed stronger in reading. However, in 2019, boys’ advantage in STEM was eliminated, with girls outperforming boys in these subjects, while maintaining their advantage in reading.
According to a new study, girls’ hard-won gains in closing the STEM achievement gap have reversed in recent years. During the COVID-19 pandemic, girls experienced a significantly larger decline in math and science test scores than their male peers, reopening the historic gender gap in middle school STEM performance.
The study authors examined three decades of test scores for eighth-grade students from the Trends in International Mathematics Study (TIMSS), an international assessment of math and science skills. In 1995, girls’ average math test score was 490, while boys’ was 495. By 2019, girls’ performance outpaced boys’ math skills, with average scores of 517 and 514, respectively. However, math scores for all students plummeted during the COVID-19 pandemic, falling to – or below – the average scores 30 years ago. For girls, the average math score in 2023 was 481, while boys’ average score was 495.
A similar pattern was observed in eighth-grade students’ TIMSS science scores. In 1995, girls averaged a score of 505 and boys averaged 520. By 2019, girls surpassed boys in their science performance, scoring an average of 525 and 520, respectively. By 2023, all students’ science scores dropped, with girls averaging 508 and boys averaging 519.
To determine whether the widening gender gaps in STEM student achievement reflect a broader pattern in student performance of if the pattern is specific to math and science, the authors examined data from two national assessments with reading results. The research team found that girls’ historic advantage in reading did not change between 2019 and 2024, suggesting girls’ setbacks in STEM are specific to those subjects and not part of an overall trend in academic performance.
Notably, differences in STEM gender gaps emerged when examining test scores of low-performing and high-performing students. Among high-achieving students in the 90th percentile, as well as those in the 50th percentile, boys outperformed girls in both math and science test scores. However, among low-performing students in the 10th percentile of scores, girls outperformed boys in math and science. Girls at all achievement levels scored higher in reading than their male peers.
Aligned with the widening gender gap among high-performing students, the authors discovered a greater decline in eighth-grade girls’ enrollment in algebra – a key pipeline to advanced STEM coursework in high school. In 2019, eighth-grade girls were slightly more enrolled in algebra than their male classmates (26.4 percent vs 24.2 percent). By 2022, girls’ experienced a sharper decline in algebra enrollment, falling by 2.9 percentage points, compared to a 1.4 percentage point decline for boys’ enrollment. By 2024, boys’ enrollment returned to its pre-pandemic levels, while girls’ enrollment remained two percentage points below 2019 rates.
“As schools and systems continue to grapple with the long tail of the pandemic, it is critical to ensure that recovery efforts do not inadvertently reinforce old inequities or allow new ones to take hold,” the authors write. “The data presented here show that the story of pandemic learning loss is not one-size-fits-all. For girls in math and science, especially those who had been gaining ground for decades, the path forward may require renewed attention, intentional support, and vigilance in monitoring progress. Rebuilding what was lost will take time — but with the right focus, it is possible not only to recover but to create a more equitable STEM education landscape than what existed before.”
The study was conducted by scholars at NWEA, a nonprofit dedicated to fostering student growth through evidence-based assessment and learning solutions.