By Kaitlyn Gerber, Carleton College
Earlier this year, JCPenny's immediately discontinued a t-shirt from their store that read "I'm too pretty to do homework, so my brother has to do it for me," while Forever 21 came under heavy criticism for a magnet reading "I'm too pretty to do math." Customers complained that the shirt was sexist and -- more importantly -- that it conveyed the message that girls are not as intelligent as boys. But while these items may cater to a dated stereotype, they inadvertently bring up an important issue in today's society: why is there still a "gender gap" between men and women when it comes to science and technology? Could it really be that, genetically, girls are inferior when it comes to doing math?
A new study says no. Published on December 12 in Notices of the American Mathematical Society, the article presents strong evidence that the gender gap is cultural, not biological. Study authors Jonathan Kane and Janet Mertz argue that, for starters, the gender gap is not universal; in fact, there are many countries, such as Japan and China, where no disparity exists between the performances of men and women. In addition, they tested several hypotheses for the gender gap in math and sciences, including the "greater male variability hypothesis" infamously described by Lawrence Summers, Harvard University's former president, in 2005. The hypothesis proposes that math ability is inherently more variable in males, meaning that there are more men than women who excel brilliantly, but also more who fail miserably.
In order to test this hypothesis, Kane and Mertz calculated the variance ratio or the variability in men's math performance compared with that of women, for 86 of countries around the world. Using test scores from the 2007 Trends for International Mathematics and Science Study (TIMSS), Kane and Mertz found that the "variance ratio" was by no means universal. In some countries, the ratios indicated much more variance in boys' performances than in girls', such as in Taiwan and Hong Kong, where the ratios were found to be 1.31 and 1.29, respectively. However, the ratios of several other countries, such as Morocco, Armenia, and Japan, were very close or equal to 1.00, indicating no disparity, and a few of the countries tested showed greater variance in girls' performances' (Tunisia, for example, had a ratio of 0.91, while Indonesia had a ratio of 0.98).
If Summers' hypothesis were true, there would not be such a notable difference in the variance ratios of each country; as a result, Kane and Mertz rejected the greater variance hypothesis as the reason for the gender gap in math and science. "People have looked at international data sets for many years", said Mertz in a press release. "What has changed is that many more non-Western countries are now participating in these studies, enabling much better cross-cultural analysis."
Kane and Mertz also looked at the hypothesis proposed by Freakonomics author Steven Levitt and Harvard Professor Roland Fryer. In a 2009 paper, Fryer and Levitt originally suggested that the single-sex environments in Muslim countries actually benefit girls' ability to learn math, rather than hampering it. However, when Kane and Mertz examined test scores in some Muslim countries, such as Oman and Bahrain, they found evidence that other factors were at work. "The girls living in some Middle Eastern countries, such as Bahrain and Oman, had, in fact, not scored very well, but their boys had scored even worse, a result found to be unrelated to either Muslim culture or schooling in single-gender classrooms," said Kane. He suggested that because many boys attend religious schools, their curricula often do not provide adequate math instruction. Similarly, test scores among girls may be artificially higher because low-performing girls may drop out before 8th grade, when the TIMSS is administered.
As a result, Kane and Mertz concluded that it was country-specific factors, rather than biological factors, that are responsible for the gender gap. To measure the status of women relative to men in each country, the authors created a gender gap index comparing income, education, health and political participation. On the whole, math achievement tends to be high in countries where overall gender equality is better. Specifically, women's political participation and salary appeared to be the main factor linking higher math scores for 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 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."
However, while women may be just as biologically capable of these abilities, there is no doubt that the gender gap in performance is still prevalent in America. Tests still show that while young children of both genders perform equally on standardized math tests, the disparity between boys and girls increases with age. Among 2007 high school graduates, for instance, boys tended to score higher on both the math portion of the SAT and the Advanced Placement Calculus exam, while fewer girls demonstrated "readiness for college-level coursework in math" on the ACT. Furthermore, a 2005 book by Yu Xie, PhD, and Kimberlee A. Shaumann, PhD, found that while women make up 35 percent of university faculty across the country, they comprise only 20 percent all professors in science and engineering.
Fortunately, these disparities have been slowly closing. In the past half century alone, the percentage of women receiving PhDs in mathematics has risen from 5% to 30%. In addition, among U.S. students who are very gifted in mathematics (scoring over a 700 on the SAT Math before turning 13), the ratio of boys to girls has decreased from 13:1 to 3:1, and is still dropping. The fact that these improvements were even possible suggests that women are not inherently inferior; they simply lacked the cultural support necessary to perform as well in the past. Mertz and Kane recommended measures such as decreasing poverty, increasing gender equality, and increasing the number of math-certified teachers in middle and high schools to improve overall performances in math and science.
"These changes would help give all children an optimal chance to succeed," said Mertz. "This is not a matter of biology: None of our findings suggest that an innate biological difference between the sexes is the primary reason for a gender gap in math performance at any level. Rather, these major international studies strongly suggest that the math-gender gap, where it occurs, is due to sociocultural factors that differ among countries, and that these factors can be changed."
As a young woman hoping for a career in science, I couldn't agree more.
Kaitlyn Gerber is a sophomore at Carleton College, where she plans to major in biology. Originally from Ridgefield, CT, she is an active soccer player and science fan, especially of ecology and astronomy.