One of the most persistent, sexist stereotypes has been that boys are better at math. Not true, says Janet Hyde, PhD, a psychology and women's studies professor at the university of Wisconsin–Madison.

In the July 25 issue of science (vol. 321, no. 5888), Hyde and her colleagues dismissed the perceived gender gap in math performance by analyzing math test scores from 7 million students, grades two through 11. The team collected standardized math assessments from 10 states and analyzed the scores for male and female students. they found no difference in average performance. Looking at the higher and lower ends of the distribution, Hyde and her colleagues again found no meaningful differences between the genders.

It's a myth she's happy to bust, she says.

"Certainly there's been a stereotype that boys are better at math that's been around for decades," says Hyde. She attributes that to studies from the 1960s and '70s that seemed to suggest a slight advantage for boys.

The stereotype is damaging because it demoralizes young girls who might want to pursue careers in mathematics and engineering, and it also may influence how teachers treat male and female students, Hyde says. she hopes these results will spur guidance counselors to encourage girls to take higher-level math and engineering courses.

So far, Hyde reports mostly positive feedback from teachers who've heard about her study.

"Teachers have been calling me and telling me, 'yes, you're right, that's exactly what I've seen in my classrooms. There's no difference.'"