But perceptions die hard - some people still insist Republicans are more anti-science than Democrats, for example, and some (not surprisingly the same people) use words like 'dismal' and 'failure' about American girls and math.

An article in

*Notices of the American Mathematical Society*by Jonathan Kane and Janet Mertz sets out to go beyond cultural jingo-ism and the cultural patronization of girls that goes on at the hands of cultural hysterics.

40 years ago, a significant gap existed between girls and boys in math, most pronounced starting at the high school level. That gap is now gone and it is dwindling worldwide also. They tackle a few key ideas; first, if there were a physical ability difference, it would be pronounced earlier on, but U.S. students who are considered highly gifted in mathematics - they can score 700 or higher on the quantitative section of the SAT prior to age 13 - show a ratio of 3:1 boys to girls. 35 years ago that ratio was 13:1 and women today are 30% of math Ph.D.s. That just can't happen so quickly if there were any biological issue.

That's not to say there are no differences; there are, but they can't be dismissed by cultural pundits who try to female teachers are telling female students they can't do math. Former Harvard President (and later Pres. Obama transition team favorite) Larry Summers got attacked by cultural mullahs for daring to discuss the "greater male variability hypothesis", which proposes that variability in intellectual abilities is intrinsically greater among males; in mathematics, boys predominate among those who excel, as well as among those who do poorly.

To test this hypothesis, Kane and Mertz calculated "variance ratios" for dozens of countries from throughout the world. These ratios compare variability in boys' math performance to variability in girls' math performance. For example, using test scores from the 2007 Trends in International Mathematics and Science Study (TIMSS), Kane and Mertz found that the variance ratio for Taiwanese eighth graders was 1.31, indicating that there was quite a bit more variability in math scores among boys than among girls. However, in Morocco, the ratio was 1.00, indicating the amount of variability observed in the two groups was identical. In Tunisia, this ratio was 0.91, indicating there was somewhat more variability in math scores among girls than among boys.

If the "greater male variability hypothesis" were true, boys' math scores should show greater variance than girls' math scores in all countries; one should also not see such big, reproducible differences from country to country. Therefore, Kane and Mertz conclude that this hypothesis does not hold up. Kane and Mertz suggest that there are sociocultural factors that differ among countries; some of these factors, such as different educational experiences and patterns of school attendance, lead to country-specific differences in boysÃ• variances and girls' variances and, thus, their variance ratios.

Kane and Mertz took the same kind of data-driven approach to examine some additional hypotheses for explaining the gender gap, such as the "single-gender classroom hypothesis" and the "Muslim culture hypothesis", both of which have been proposed in recent years by various people, including Steven Levitt of "Freakonomics" fame. Again, Kane and Mertz found that the data do not support these hypotheses. Rather, they observed no consistent relationship between the gender gap and either co-educational schooling or most of the country's inhabitants being Muslim.

They also examined the "gap due to inequity hypothesis", which proposes that the gender gap in math performance is due to social and cultural inequities between males and females. To examine this hypothesis, they used an international gender gap index that compares the genders in terms of income, education, health, and political participation. Relating these indices to math scores, they concluded that math achievement for both boys and girls tends to be higher in countries where gender equity is better. In addition, in wealthier countries, women's participation and salary in the paid labor force was the main factor linked to higher math scores for students of both genders. "We found that boys as well as girls tend to do better in math when raised in countries where females have better equality, and that's both new and important," says Kane. "It makes sense that when women are well educated and earn a good income, the math scores of their children of both genders benefit."

Mertz adds, "Many folks believe gender equity is a win-lose zero-sum game: If females are given more, males end up with less. Our results indicate that, at least for math achievement, gender equity is a win-win situation."