High school boys outscored girls in standardized math tests in the United States. But girls performed just as well as their male counterparts in Norway, Sweden, and other countries with the most economic equality, according to researchers from Northwestern University.

But girls outscored boys in reading across all 40 countries the team studied.

The findings, published in today's issue of the journal Science, add new insights to a raging debate over gender differences in learning, the relative roles of culture and brain biology, and the question of whether boys or girls are being shortchanged by the school system.

"This is a very nice piece of work they've done," said Louann Brizendine, a neurobiologist at the University of California San Francisco, who had no connection to the work. "It shows scientifically that the more gender-equal cultures stimulate female brains to develop math and reading skills."

Others were less impressed.

"It doesn't change the basic differences in the male and female brains," said Michael Gurian, a family therapist and author of

Boys and Girls Learn Differently

and other books on gender. Those brain differences allow men to outperform women, on average, only in certain areas of math that involve spatial reasoning and symbolic thinking, he said.

The new study took the math and reading scores from the Programme for International Student Assessment, which tested 276,165 teenagers around the world in both math and reading skills. The test, given to 15-year-olds, is designed to be culturally unbiased, said Northwestern University finance professor Paola Sapienza, one of the study's authors.

She and her colleagues noticed that while boys overall did better on the math part of the test, girls did as well or slightly better than boys in Northern Europe. To Sapienza, who grew up in Italy, it suggested a cultural pattern.

To see if there was a connection to gender equality, she used something called Gender Gap Index, a measurement of access to education and well-paying jobs collected by the World Economic Forum. In that index, the United States ranks 16th, behind Australia, Canada, New Zealand, and a handful of European countries.

'Intriguing'

With perfect equality being a 1, she said, Sweden scores .81, the United States .70, and Italy .64.

As another measure of gender status, she also looked at the Worldwide Values Survey, which canvassed people with questions such as "Do you think university education is more for boys than girls?" and "Do you think women working outside the home are not taking good care of their children?"

Attitudes about gender and economic equality ran parallel to girls' high math scores, she said.

But in a twist, the countries that showed the most economic equality had the biggest gaps in reading scores, with the boys lagging. "It's a factor I find intriguing," she said.

But even in those countries, the high scores of the girls didn't come at the expense of the boys - both sexes scored relatively high compared with the other countries.

Sapienza said the study did not claim to uncover why economic and attitudinal equality are linked to test scores. And while it does suggest that culture plays a role in math performance, that doesn't eliminate the possible influence of biology.

Certain patterns held true across countries, she said. The average girl, for example, did better in arithmetic than geometry, and better on reading than in math. For the average boy, it was the reverse.

'The real difference'

Family counselor Gurian said the study would have done better to separate arithmetic, where girls perform as well as boys, and what he calls "iconic and symbolic math," where boys tend to outperform girls. "It's there that the real difference is."

And that gap, he said, is due to brain differences that should be addressed in education. He acknowledged that some boys and some girls perform at the top in any field. But on average, he said, boys will have more trouble when faced with a blank page and told to write an essay.

Students who tend to be spatial thinkers - most of them male, he said - tend to write better if asked to create a drawing first to sketch out their thoughts.

Likewise, the more verbally oriented students - usually girls - can improve their math performance if asked to talk over a problem before solving it.

"We're trying to make education more diverse," he said. But overall, he said, the system is skewed toward females, thus leading to a preponderance of girls going to college.

Today the ratio of U.S. college boys to girls is 43 to 57. "Boys are really struggling," he said.

Yes, there are brain differences between men and women but those can be shaped by culture, said Brizendine, of the University of California San Francisco. Brizendine wrote

The Female Brain

.

"Cultural environment seriously impacts brain circuit growth," she said. That is, the structure of your brain depends on everything that happens to you, including feedback from parents, peers, and culture in general.

So it's not out of the question that Swedish girls have more mathematical brains, on average, than U.S. girls, thanks to a different environment.

"Improving the role of women in society can go a very long way toward developing the potential of its female brain power," she said.

But do lagging college admissions suggest we're now neglecting male brainpower? Brizendine said it's possible that after years of discrimination against girls, they now are getting more attention.

Peter Kuriloff, a professor at the University of Pennsylvania's Graduate School of Education, says gender differences in learning are tiny compared with the differences between individual boys and girls.

And he's not convinced there's any serious discrimination against boys outside of class and racial discrimination.

All of the focus on anti-male discrimination "masks the really important stuff that's going on," he said. If you look at African American boys, 25 percent end up in jail - that is a crisis."

As for brain differences, he said, not that much is known about the connection with learning, "but there's a lot of malarkey."

In his experience, girls may be getting better grades and graduating from college in greater numbers because they're working harder than boys. "Every time you've given girls a chance, they've done better than boys in school," he said. "There's been a push to put them back in a box."

Contact staff writer Faye Flam

at 215-854-4977 or fflam@phillynews.com.