Chicago, U.S.- Despite persistent stereotypes, girls in the United States now perform just as well as boys on standardized tests in math, United States researchers said on Thursday.

'There just aren't gender differences any more in math performance,' said University of Wisconsin-Madison psychology professor Janet Hyde, whose study was published in the journal Science.

Prof Hyde and colleagues sifted through math scores from 7 million students from 10 states tested in accordance with the No Child Left Behind Act, as well as the Scholastic Aptitude Test or SAT, a standardised test used for college admissions.

She said there is no difference in innate ability that can explain why women are so under-represented in math and science careers. Currently, women make up only 15 per cent of doctoral candidates in engineering programmes, for example.

Although girls take just as many advanced high school math courses today as boys and women earn nearly half of all undergraduate degrees in math, Prof Hyde said many parents and teachers still believe girls struggle in math.

'We need to get the word out to the high school teachers and counsellors that girls are as good as boys at math,' she said.

The researchers calculated an 'effect size', which measures the degree of difference between girls' and boys' average math scores in standardised units. The effect sizes they found - ranging from 0.01 and 0.06 - were basically zero.

Testing shortfalls
They also looked for gender discrepancies at the highest levels of mathematical ability, checking to see if more boys fell into the top percentiles of scores than girls.

'While we did find more boys than girls above the 99th percentile at a 2-to-1 ratio, still, 33 per cent of those kids who are above the 99th percentile are girls,' she said.

However, in Asian Americans, the reverse was true.

'More Asian-American girls than boys scored above the 99th percentile,' she said. Rather than being a gender-based difference, Prof Hyde thinks it may be a cultural difference.

They also checked to see if boys did better than girls in solving complex math problems. While they found no difference, they did notice that overall, state tests lacked questions involving complex problem solving.

'If these tests have just the lower-level kinds of items, teachers are not going to teach more complex problem solving,' Prof Hyde said.

That may leave US students unprepared for careers in math, science and engineering, she said.

The team also looked at differences in SAT scores, which typically show boys scoring higher than girls in math.

Prof Hyde said the problem is that the SAT is not administered to a random sample of American students but to a selective set of college-bound students.

According to her, about 100,000 more girls than boys take the test in any given year, which likely means that the boys who take it tend to be on the higher end academically.

'It's probably just a sampling artifact,' she said.

Prof Hyde thinks mothers who grew up with math stereotypes need to be especially careful. 'Even if you believe you can't do math, you can just keep quiet about it,' she said. -- REUTERS