The notion that boys are better than girls at math simply doesn't add up, according to a study published today in the journal Science.
An analysis of standardized test scores from more than 7.2 million students in grades 2 through 11 found no difference in math scores for girls and boys, contradicting the pervasive belief that most women aren't hard-wired for careers in science and technology.
The study also undermined the assumption -- infamously espoused by former Harvard University President Lawrence H. Summers in 2005 -- that boys are more likely than girls to be math geniuses. Girls scored in the top 5% almost as often as boys, the data showed.
"Both parents and teachers continue to hold the stereotype that boys are better than girls" at math, said psychologist Janet Hyde of the University of Wisconsin at Madison, who led the study. "That's just not accurate."
Hyde and her colleagues examined detailed data from math tests administered between 2005 and 2007 as part of the No Child Left Behind initiative.
Comparing the average scores of girls and boys in California and nine other states, the researchers found that neither gender consistently outpaced the other in any state or at any grade level.
Even on test questions from the National Assessment of Education Progress that were designed to measure complex reasoning skills, the gender differences were minuscule, according to the study.
"There's nothing in any of these data that would suggest that girls can't do math or aren't doing well in math," said Diane Halpern, a professor of psychology at Claremont McKenna College who was not involved in the study.
However, she noted that girls generally scored better on tests closely aligned with the classroom curriculum, including the standardized tests used for No Child Left Behind.
Boys typically score higher than girls on the math portion of the SAT, a fact often cited as evidence of greater math ability.
But since more girls than boys take the college entrance exam, the results aren't comparable, Hyde said.
Studies in the 1990s found that boys and girls in elementary school scored equally well on math tests but that by the time students reached high school, boys outscored girls on tests involving complex problem-solving.
Hyde said that pressure to get into selective colleges has prompted girls to take more advanced math classes, including calculus, and she said that may explain the improvement in test scores.
Hyde said it might take time for the new data to dispel lingering stereotypes, and she remained worried that girls would continue to be steered "away from careers that require a lot of math, like engineering."
Cathy Kessel, president of the Assn. for Women in Mathematics, said that even nonacademic issues like child care could dissuade young women from entering math-oriented fields.
"There may not be any one factor," said Kessel, a consultant in math education in Berkeley. "It's probably more complicated."